1.
One ball is placed on the edge of a table and allowed to fall to the floor.
The other is rolled rapidly across the table and falls onto the floor
They have the same mass. If they're dropped from the table at the same time, which ball will hit the floor first?
Correct Answer
C. They will hit at the same time.
Explanation
Both balls will hit the floor at the same time because the force of gravity acts on both objects equally, regardless of their initial velocities or methods of falling. The mass of the balls does not affect the rate at which they fall. Therefore, both balls will experience the same acceleration due to gravity and will reach the floor simultaneously.
2.
Why would a flat sheet of paper and a wad of paper with the same mass not fall through the air at the same time
Correct Answer
A. Air Resistance
Explanation
A flat sheet of paper and a wad of paper with the same mass would not fall through the air at the same time due to air resistance. Air resistance is the force that opposes the motion of an object through the air. The wad of paper, being more compact and less spread out, would experience more air resistance compared to the flat sheet of paper. This increased air resistance would slow down the wad of paper more, causing it to fall at a slower rate than the flat sheet of paper.
3.
What type of friction opposes two surfaces sliding past each other?
Correct Answer
B. Sliding Friction
Explanation
Sliding friction is the correct answer because it is the type of friction that opposes the motion of two surfaces sliding past each other. When two surfaces slide against each other, the irregularities in their surfaces create resistance, resulting in sliding friction. This type of friction is commonly observed when objects are pushed or pulled across a surface, such as when a book is dragged across a table.
4.
When is something weightless?
Correct Answer
B. Never
Explanation
Weight is the force exerted by gravity on an object. It is a measure of the mass of an object multiplied by the acceleration due to gravity. Therefore, something is never weightless as long as it has mass and is subject to the force of gravity. Even in space or on the moon, where the force of gravity is weaker, objects still have weight.
5.
What type of friction causes a rolling object on a surface to stop?
Correct Answer
A. Rolling Friction
Explanation
Rolling friction is the correct answer because when a rolling object moves on a surface, the friction between the object and the surface causes it to gradually slow down and eventually stop. This type of friction occurs when there is contact between the rolling object and the surface, and it acts in the opposite direction to the motion of the object. Rolling friction is typically lower than sliding friction, which occurs when an object slides across a surface, and static friction, which prevents an object from moving when a force is applied to it.
6.
What type of friction prevents two surfaces moving past eachother?
Correct Answer
C. Static Friction
Explanation
Static friction is the type of friction that prevents two surfaces from moving past each other. It occurs when two objects are in contact with each other but not moving relative to each other. The force of static friction acts in the opposite direction of the force applied to try to move the objects. It is the frictional force that must be overcome in order to initiate motion between the two surfaces. Once the objects start moving, the frictional force changes to kinetic friction.
7.
causes a box you are pushing across the floor to stop when you stop pushing.
Correct Answer
Sliding Friction
Explanation
Sliding friction is the force that opposes the motion of an object as it slides across a surface. When you push a box across the floor, there is a force of sliding friction acting in the opposite direction, which causes the box to stop when you stop pushing. Sliding friction occurs due to the microscopic roughness of the surfaces in contact, which creates interlocking between them and resists the motion. As a result, the box experiences a frictional force that counteracts its motion and brings it to a stop when the pushing force is no longer applied.
8.
Two surfaces that are not moving past each other have .
Correct Answer
Static Friction
Explanation
When two surfaces are not moving past each other, they experience static friction. Static friction is the force that prevents the surfaces from sliding against each other. It acts in the opposite direction of the impending motion and can vary in magnitude depending on the materials and the force applied. The value of static friction is always equal to or less than the force applied, keeping the surfaces in equilibrium and preventing any relative motion between them.
9.
Weight is measured in units called , while mass is measured in units called grams and kilograms.
Correct Answer
Newtons
Explanation
Weight is the force exerted on an object due to gravity, and it is measured in units called Newtons. Mass, on the other hand, is a measure of the amount of matter in an object and is measured in units called grams and kilograms. Therefore, the correct answer is Newtons.
10.
The amount of gravitational force between two objects depends on their masses and the between them.
Correct Answer
Distance
Explanation
The amount of gravitational force between two objects depends on their masses and the distance between them. This is because gravity is a force that weakens with distance. The greater the distance between two objects, the weaker the gravitational force between them. Similarly, the closer the objects are to each other, the stronger the gravitational force. Therefore, distance plays a crucial role in determining the strength of the gravitational force between two objects.
11.
An object's is the measure of the force of gravity on that object.
Correct Answer
Weight
Explanation
Weight is the measure of the force of gravity acting on an object. It is a measure of how heavy an object is and is dependent on the mass of the object and the acceleration due to gravity. Weight is typically measured in units of force, such as pounds or newtons. The greater the mass of an object, the greater its weight will be. Similarly, the greater the acceleration due to gravity, the greater the weight of an object will be. Weight is different from mass, as mass is a measure of the amount of matter in an object, while weight is a measure of the force acting on that matter.
12.
is the force that every object in the universe exerts on every other object.
Correct Answer
Gravity
Explanation
Gravity is the force that every object in the universe exerts on every other object. It is a fundamental force of nature that causes objects with mass to be attracted to one another. This force is responsible for keeping planets in orbit around the sun, objects falling to the ground, and the formation of galaxies. Gravity is described by Isaac Newton's law of universal gravitation and Albert Einstein's theory of general relativity. It is a force that is always present and acts over long distances, shaping the structure and behavior of the universe.
13.
According to the , when a bowling ball strikes the pins, the momentum lost by the bowling ball is equal to the momentum gained by the pins.
Correct Answer
Conservation of Momentum
Explanation
The principle of conservation of momentum states that the total momentum of a system remains constant if no external forces act on it. In the case of a bowling ball striking the pins, the momentum lost by the bowling ball (due to its mass and velocity) is equal to the momentum gained by the pins (which are initially at rest). This is because the momentum lost by the bowling ball is transferred to the pins, causing them to move. Therefore, the principle of conservation of momentum is applicable in this situation.
14.
A property of a moving object resulting from its mass and velocity is .
Correct Answer
Momentum
Explanation
Momentum is a property of a moving object that is determined by both its mass and velocity. It is a vector quantity, meaning it has both magnitude and direction. The momentum of an object can be calculated by multiplying its mass by its velocity. The greater the mass or velocity of an object, the greater its momentum will be. Momentum is important in understanding the behavior of objects in motion, as it helps to determine how they will interact with other objects or forces.
15.
A new force acting on an object causes the object to accelerate in direction of the force; this is .
Correct Answer
Newton's Second Law of Motion
Newton's 2nd Law of Motion
Explanation
When a new force is applied to an object, the object will accelerate in the direction of that force. This statement is a concise explanation of Newton's Second Law of Motion, which states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass. The law can also be referred to as Newton's 2nd Law of Motion.
16.
The force exerted by air on a moving object is called _______________.
Correct Answer
Air Resistance
Explanation
Air resistance is the force exerted by air on a moving object. As an object moves through the air, the air molecules collide with the object, creating a resistance force that opposes the motion. This force depends on factors such as the speed and surface area of the object. Air resistance is particularly noticeable for objects moving at high speeds, such as cars or airplanes, and it can significantly affect their motion and performance.
17.
When a car travels around a curve in the road, helps to keep the car traveling in a curved path.
Correct Answer
Centripetal Acceleration
Explanation
Centripetal acceleration is the correct answer because it is the force that acts towards the center of the curve, allowing the car to maintain its curved path. This force is necessary to counteract the tendency of the car to continue traveling in a straight line due to inertia. Without centripetal acceleration, the car would not be able to navigate curves and would instead continue traveling in a straight line.
18.
When an object moves in a circle, acts to accelerate the object toward the center of that circle.
Correct Answer
Centripetal Force
Explanation
When an object moves in a circle, it experiences a centripetal force that acts towards the center of that circle. This force is necessary to keep the object moving in a curved path and prevents it from moving in a straight line. Without this force, the object would continue moving in a straight line tangent to the circle. The centripetal force can be provided by various factors such as tension in a string, gravitational force, or friction. It is essential for maintaining circular motion and ensuring that the object stays on its curved path.
19.
A ball thrown across a football field is an example of a(n) .
Correct Answer
Projectile
Explanation
A ball thrown across a football field is an example of a projectile because it follows a curved path known as a trajectory. The ball is launched with an initial velocity and then moves under the influence of gravity, causing it to follow a parabolic path. The motion of the ball is independent of any external forces once it is in the air, making it a projectile.
20.
The largest velocity reached by a falling object is its .
Correct Answer
Terminal Velocity
Explanation
The largest velocity reached by a falling object is its terminal velocity. Terminal velocity is the maximum velocity that an object can reach while falling through a fluid, such as air or water. When an object first starts falling, it accelerates due to the force of gravity. However, as the object gains speed, the drag force from the fluid increases and eventually balances out the force of gravity. At this point, the object stops accelerating and reaches a constant velocity, known as terminal velocity.
21.
The phrase "to every action there is an equal and opposite reaction" is .
Correct Answer
Newton's 3rd Law of Motion
Newton's Third Law of Motion
Explanation
The given correct answer is Newton's 3rd Law of Motion or Newton's Third Law of Motion. This law states that for every action, there is an equal and opposite reaction. It means that when an object exerts a force on another object, the second object exerts a force of equal magnitude but in the opposite direction on the first object. This law is fundamental in understanding the interactions between objects and is widely used in physics and engineering.
22.
Direction and distance is...
Correct Answer
C. Displacement
Explanation
Displacement is the correct answer because it refers to the change in position of an object in a particular direction. It takes into account both the distance traveled and the direction of travel. Velocity is the rate at which an object changes its position, distance is the total length of the path traveled, and inertia is the tendency of an object to resist changes in its motion. However, only displacement accurately describes the concept of direction and distance.
23.
The measure of how far something moved is...
Correct Answer
E. Distance
Explanation
Distance is the measure of how far something moved. It refers to the total path length traveled by an object, regardless of its direction or any changes in its position. It is a scalar quantity, meaning it only has magnitude and no specific direction. Displacement, on the other hand, is a vector quantity that refers to the change in position of an object from its starting point to its ending point, taking into account direction. Inertia is the tendency of an object to resist changes in its motion. Velocity is the rate at which an object changes its position in a specific direction.
24.
The distance per unit of time is...
Correct Answer
C. Speed
Explanation
Speed is the correct answer because it represents the distance traveled per unit of time. It is a scalar quantity that only considers the magnitude of the movement, disregarding its direction. In contrast, velocity is a vector quantity that includes both the magnitude and direction of the movement. Inertia refers to an object's resistance to changes in motion, displacement is the change in position, and distance is the total length traveled. Therefore, speed best represents the distance per unit of time.
25.
Speed and direction is...
Correct Answer
B. Velocity
Explanation
Velocity is the correct answer because it refers to the speed and direction of an object. Speed only refers to the magnitude of an object's motion, while velocity includes both the magnitude and direction. Displacement refers to the change in position of an object, and inertia refers to an object's resistance to changes in motion. Therefore, velocity is the most appropriate choice that encompasses both speed and direction.
26.
Positive acceleration speeds up.
Correct Answer
A. True
Explanation
Positive acceleration refers to an increase in velocity over time. When an object experiences positive acceleration, it means that its speed is increasing. Therefore, positive acceleration indeed speeds up an object. Thus, the statement "Positive acceleration speeds up" is true.
27.
Negative Acceleration slows down.
Correct Answer
A. True
Explanation
Negative acceleration refers to the decrease in velocity over time. When an object experiences negative acceleration, it means that its speed is decreasing, causing it to slow down. Therefore, the statement "Negative acceleration slows down" is true.
28.
Force can cause the of an object to change.
Correct Answer
Motion
Explanation
That is how force and motion are related
29.
What property of matter is inertia related to?
Correct Answer
C. Mass
Explanation
Inertia is the property of matter that describes its resistance to changes in motion. It is directly related to mass, as objects with greater mass have greater inertia. This means that it takes more force to accelerate or decelerate an object with a larger mass compared to an object with a smaller mass. Therefore, the correct answer is mass.
30.
A car engine changes chemical potential energy into the energy of a moving car.
Correct Answer
Kinetic
Explanation
A car engine converts the stored chemical potential energy in fuel into the kinetic energy of a moving car. As the fuel combusts, it releases energy that is used to drive the pistons, which in turn powers the car's wheels. This kinetic energy allows the car to move and perform work.
31.
An orange in a tree has energy due to Earth pulling down on it.
Correct Answer
Gravitational Potential
Explanation
The explanation for the given correct answer is that the energy of the orange in the tree is due to the gravitational potential. Gravitational potential energy is the energy possessed by an object due to its position in a gravitational field. In this case, the orange is elevated in the tree, and Earth's gravitational force is pulling it downwards. This creates a potential energy that can be converted into kinetic energy if the orange falls from the tree.
32.
The total energy of a system remains _____________.
Correct Answer
Constant
Explanation
The total energy of a system remains constant. This means that the total amount of energy within the system does not change over time. Energy can be transformed from one form to another, but the total amount remains constant. This principle is known as the conservation of energy and is a fundamental concept in physics. It implies that energy cannot be created or destroyed, only transferred or converted into different forms. Therefore, regardless of any transformations or exchanges that occur within the system, the total energy remains the same.
33.
You convert kinetic energy into thermal energy when you rub two sticks together because of
Correct Answer
Friction
Explanation
Rubbing two sticks together creates friction between the surfaces of the sticks. Friction is the force that opposes the motion of two objects in contact with each other. When the sticks are rubbed together, the friction between them causes the molecules on the surfaces of the sticks to vibrate and generate heat. This heat energy is a form of thermal energy, which is the energy associated with the motion of particles within a substance. Therefore, the conversion of kinetic energy (from the rubbing motion) into thermal energy occurs due to the presence of friction.
34.
The conversion of potential energy to kinetic energy follows the .
Correct Answer
Law of Conservation of Energy
Explanation
The conversion of potential energy to kinetic energy follows the Law of Conservation of Energy. According to this law, energy cannot be created or destroyed, but it can only be transferred or transformed from one form to another. In the case of potential energy being converted to kinetic energy, the total amount of energy remains constant. This means that the potential energy is transformed into kinetic energy without any loss or gain of energy.
35.
Nutritionists use the to measure how much energy we get from foods.
Correct Answer
Calorie
Explanation
Nutritionists use the term "calorie" to measure the amount of energy we obtain from the foods we consume. A calorie is a unit of measurement that quantifies the energy content of food. By understanding the number of calories in a particular food item, nutritionists can assess its potential impact on our energy intake and overall health.
36.
The law of states that energy cannot be created or destroyed.
Correct Answer
Conservation of Energy
Explanation
The law of conservation of energy states that energy cannot be created or destroyed. This means that the total amount of energy in a closed system remains constant. Energy can only be transferred or transformed from one form to another. This principle is based on the understanding that energy is a fundamental property of the universe and is always conserved, regardless of the transformations it undergoes.
37.
The energy stored in foods and fuels is potential energy.
Correct Answer
Chemical
Explanation
The energy stored in foods and fuels is potential energy because it is stored in the chemical bonds of molecules. When these bonds are broken, energy is released, which can be used to do work. This energy is in the form of potential energy because it has the potential to be converted into other forms, such as kinetic energy or thermal energy.
38.
The potential energy of an object depends on its
Correct Answer
Position
Explanation
The potential energy of an object depends on its position. This is because potential energy is the energy that an object possesses due to its position or condition. The higher an object is positioned, the greater its potential energy will be. Similarly, the lower an object is positioned, the lesser its potential energy will be. Therefore, the position of an object plays a crucial role in determining its potential energy.
39.
The amount of kinetic energy a moving object has depends on its mass and its
Correct Answer
Velocity
Explanation
The amount of kinetic energy a moving object has depends on its mass and its velocity. Kinetic energy is the energy possessed by an object due to its motion. The velocity of an object refers to its speed in a given direction. The faster an object moves, the greater its velocity and therefore the greater its kinetic energy. Similarly, the more mass an object has, the greater its kinetic energy. Therefore, both mass and velocity are factors that determine the amount of kinetic energy an object possesses.
40.
The discovery that uranium is a radioactive element was made by...
Correct Answer
A. Henri Becquerel
Explanation
Henri Becquerel is credited with discovering that uranium is a radioactive element. In 1896, while conducting experiments with uranium salts, Becquerel accidentally discovered that photographic plates stored near the uranium emitted their own radiation. This led him to conclude that uranium was spontaneously emitting radiation, a groundbreaking discovery that laid the foundation for the field of nuclear physics. Marie Curie, on the other hand, is known for her pioneering research on radioactivity and her discovery of the elements polonium and radium. John Stilmoich and John Curie are not associated with the discovery of uranium's radioactivity.
41.
Marie and Pierre Curie discovered the elements radium and...
Correct Answer
C. Polonium
Explanation
Marie and Pierre Curie discovered the elements radium and polonium. Polonium is a highly radioactive element that was named after Marie Curie's home country, Poland. It was the first element to be discovered by the Curies through their groundbreaking research on radioactivity.
42.
Because of the strong force protons are repelled by protons.
Correct Answer
B. False
Explanation
Attracted to
43.
A form of raidation that travels as waves is a...
Correct Answer
B. Gamma ray
Explanation
Gamma rays are a form of radiation that travel as waves. They have high energy and are able to penetrate through various materials. Gamma rays are produced during nuclear reactions and radioactive decay. They are often used in medical imaging and radiation therapy. Unlike alpha particles and beta particles, gamma rays do not have mass or charge, making them highly penetrating and capable of causing damage to living tissues. Therefore, the correct answer is gamma ray.
44.
Energy in the sun is produced as a result of nuclear fusion reactions.
Correct Answer
A. True
Explanation
NOT nuclear fission
45.
The type of nuclear reaction that produces a nucleus withwith a large mass from nuclei of lower masses is a fission reaction.
Correct Answer
B. False
Explanation
Fusion
46.
The constant rate at which a radioactive element decays is its....
Correct Answer
A. Half-life
Explanation
The half-life of a radioactive element refers to the time it takes for half of the radioactive atoms in a sample to decay. It is a constant rate that is unique to each radioactive element. This means that regardless of the initial amount of the element, after one half-life, half of it will have decayed, and after two half-lives, three-quarters will have decayed, and so on. Therefore, the correct answer is half-life.
47.
The radioisotope that is used to detect and treat thyroid cancer is..
Correct Answer
D. I-131
Explanation
I-131 is the correct answer because it is a radioisotope commonly used in the detection and treatment of thyroid cancer. It emits beta and gamma radiation, which can target and destroy cancer cells in the thyroid gland. The radioactive iodine is taken up by the thyroid tissue, allowing for the detection of any abnormal growth or cancerous cells. Additionally, I-131 can be used in higher doses to treat thyroid cancer by destroying the thyroid tissue and any remaining cancer cells.
48.
Radiation can be used to stop ze type of cancer cells from growing.
Correct Answer
A. True
Explanation
Radiation therapy is a common treatment for cancer that uses high-energy radiation to target and destroy cancer cells. It works by damaging the DNA of cancer cells, preventing them from growing and dividing. This can help stop the growth and spread of cancer. Therefore, the statement that radiation can be used to stop certain types of cancer cells from growing is true.
49.
To determine how much radiation is present in an area, a Geiger counter is less useful than a bubble chamber
Correct Answer
B. False
Explanation
more useful
50.
The use of carbon-14 to determine the age of fossils is called...
Correct Answer
D. Radioactive Dating
Explanation
Radioactive dating is the correct answer because carbon-14, a radioactive isotope, is used to determine the age of fossils. Carbon-14 decays over time, and by measuring the amount of carbon-14 remaining in a fossil, scientists can estimate its age. This method relies on the principle that carbon-14 is constantly being produced in the atmosphere and taken up by living organisms, so when an organism dies, the carbon-14 begins to decay. By comparing the ratio of carbon-14 to carbon-12 in a fossil, scientists can calculate its age.