1.
What is the net force on the car?
Correct Answer
B. 3N to the right
Explanation
The net force on the car is 3N to the right. This means that there are forces acting on the car in opposite directions, but the force to the right is greater than the force to the left by 3N. As a result, there is a net force of 3N acting on the car in the rightward direction.
2.
What is the net force on the object?
Correct Answer
C. 10 N to the right
Explanation
The net force on the object is 10 N to the right. This means that the total force acting on the object in the right direction is 10 N. There are no other forces acting on the object in the opposite direction, so the net force is solely 10 N to the right.
3.
Which of these objects would exhibit the greatest resistance to a change in its motion?
Correct Answer
A. One that has a mass of 5000g
Explanation
An object with a greater mass would exhibit the greatest resistance to a change in its motion. This is because inertia, which is the tendency of an object to resist changes in its motion, is directly proportional to the mass of the object. Therefore, the object with a mass of 5000g would have the greatest inertia and resistance to a change in its motion compared to the other objects listed.
4.
Which universal force exerts force on every other object?
Correct Answer
D. Gravitational
Explanation
Gravitational force is the universal force that exerts a force on every other object. It is the force of attraction between two objects with mass. This force is responsible for holding planets in orbit around the sun, keeping objects on the ground, and determining the motion of celestial bodies. Unlike other forces, gravitational force is always attractive and acts over long distances. It is the force that governs the motion of objects in the universe.
5.
A plane flying through the air is what kind of friction?____________________________________
Correct Answer
B. Fluid
Explanation
When a plane is flying through the air, the friction that is present is known as fluid friction. This type of friction occurs when an object moves through a fluid, such as air or water. In the case of a plane, as it moves through the air, the air molecules exert a resistance force on the plane's surface, creating fluid friction. This friction is important to consider in aerodynamics and affects the plane's speed and efficiency.
6.
What property of matter explains why an object at rest stays at rest unless acted up by a force?
Correct Answer
C. Inertia
Explanation
Inertia is the property of matter that explains why an object at rest stays at rest unless acted upon by a force. It is the tendency of an object to resist changes in its motion, whether it is at rest or in motion. Inertia is directly related to an object's mass, where objects with greater mass have greater inertia. This means that it requires more force to overcome the inertia of a heavier object and put it into motion. Therefore, inertia is the correct answer to this question.
7.
Which of Newton’s laws says that mass times acceleration equals the net force
(m x a = f) acting on an object?
Correct Answer
B. Second law of motion (law of acceleration)
Explanation
The second law of motion, also known as the law of acceleration, states that the net force acting on an object is equal to the product of its mass and acceleration. This law is represented by the equation f = m x a, where f represents the net force, m represents the mass of the object, and a represents the acceleration. Therefore, the correct answer is the second law of motion (law of acceleration).
8.
Force that opposes motion between two surfaces
Correct Answer
C. Friction
Explanation
Friction is the force that opposes motion between two surfaces. When two objects are in contact and one tries to move relative to the other, friction acts in the opposite direction, making it difficult for the objects to slide past each other. Friction is caused by the irregularities on the surfaces of the objects, which interlock and resist relative motion. It is a fundamental force that can be found in various everyday situations, such as walking, driving, or even holding objects.
9.
The rougher the surface, the less the friction.
Correct Answer
B. False
Explanation
Friction is actually greater on rough surfaces compared to smooth surfaces. This is because rough surfaces have more contact points between the two objects, which increases the frictional force. Smooth surfaces have fewer contact points, resulting in less friction. Therefore, the statement that the rougher the surface, the less the friction is false.
10.
The greater the mass of an object, the greater the gravitational force.
Correct Answer
A. True
Explanation
According to Newton's law of universal gravitation, the gravitational force between two objects is directly proportional to the product of their masses. This means that as the mass of an object increases, the gravitational force it experiences also increases. Therefore, it is true that the greater the mass of an object, the greater the gravitational force.
11.
Which of Newton's Laws explains why we need seat belts in a car?
Correct Answer
C. Newton's First Law
Explanation
Newton's First Law, also known as the law of inertia, explains why we need seat belts in a car. This law states that an object at rest will stay at rest, and an object in motion will stay in motion, unless acted upon by an external force. In the case of a car, when it suddenly stops or changes direction, the passengers inside the car will continue to move forward due to their inertia. Without seat belts, they would be thrown forward and potentially injured. Seat belts provide the necessary external force to restrain the passengers and prevent them from being thrown forward during sudden stops or collisions.
12.
A student pushes a stalled car with a force of 60 N. What is the force exerted by the car on his hands?
Correct Answer
D. 60 N
Explanation
When a student pushes a car with a force of 60 N, according to Newton's third law of motion, the car exerts an equal and opposite force on the student's hands. Therefore, the force exerted by the car on his hands is also 60 N.
13.
A 10 kg ball is accelerated 500 m/s² by a force of
Correct Answer
B. 5000 N
Explanation
The correct answer is 5000 N because the force applied to an object is directly proportional to its acceleration according to Newton's second law of motion. The formula for this relationship is F = m*a, where F is the force, m is the mass of the object, and a is the acceleration. In this case, the mass of the ball is given as 10 kg and the acceleration is given as 500 m/s^2. By rearranging the formula, we can solve for the force: F = m*a = 10 kg * 500 m/s^2 = 5000 N. Therefore, a force of 5000 N is required to accelerate the 10 kg ball at 500 m/s^2.
14.
For any object, the greater the force that’s applied to it, the greater its _____________will be.
Correct Answer
A. Acceleration
Explanation
When a greater force is applied to an object, it will experience a larger acceleration. This is because acceleration is directly proportional to the force acting on the object, according to Newton's second law of motion. The greater the force, the greater the acceleration the object will have. Therefore, the correct answer is acceleration.
15.
Wearing of tires when driving is an example of friction.
Correct Answer
A. True
Explanation
The wearing of tires when driving is an example of friction because friction is the force that opposes the motion between two surfaces in contact, causing them to wear or deteriorate. When a vehicle is in motion, the tires make contact with the road surface, and the friction between them causes the tires to wear down over time. This can be observed by the gradual loss of tread on the tires, which is a result of the friction between the rubber and the road surface.
16.
Skiing is an example of what kind of friction
Correct Answer
B. Sliding
Explanation
Skiing is an example of sliding friction because when skis slide over the snow or ice, there is a resistance between the two surfaces that allows the skier to glide. Sliding friction occurs when two objects slide past each other, creating frictional forces that oppose the motion. In the case of skiing, the skis make contact with the snow or ice, and the friction between the skis and the surface allows the skier to control their speed and direction.
17.
The type of force that is causes atoms of Hydrogen to split and fuse together on the sun to produce Helium.
Correct Answer
C. Nuclear
Explanation
The correct answer is nuclear. Nuclear force is responsible for causing the atoms of Hydrogen to split and fuse together on the sun to produce Helium. This process, known as nuclear fusion, occurs at extremely high temperatures and pressures in the sun's core. The strong nuclear force overcomes the electrostatic repulsion between the positively charged protons, allowing them to come close enough together for the attractive nuclear force to bind them together, releasing a tremendous amount of energy in the process.
18.
Which has more momentum, a go-cart moving 25 mph or a Chevy S10 pick up moving at 70 mph?
Correct Answer
B. S10 pick-up
Explanation
The momentum of an object is directly proportional to its mass and velocity. In this case, the Chevy S10 pick-up is moving at a higher velocity (70 mph) compared to the go-cart (25 mph). Since both objects have different masses, the pick-up truck will have more momentum due to its higher velocity.
19.
What is the net force on a 1,200 kg object accelerating at 3 m/s2.?
Correct Answer
D. 3600 N
Explanation
The net force on an object can be calculated using the equation F = m*a, where F is the force, m is the mass, and a is the acceleration. In this case, the mass of the object is given as 1,200 kg and the acceleration is given as 3 m/s^2. Plugging these values into the equation, we get F = 1,200 kg * 3 m/s^2 = 3,600 N. Therefore, the correct answer is 3,600 N.
20.
Force of attraction between any two objects in the universe
Correct Answer
C. Gravity
Explanation
Gravity is the force of attraction between any two objects in the universe. It is responsible for keeping objects grounded on Earth and for the motion of planets, stars, and galaxies. Gravity is a fundamental force that acts between all objects with mass. It is what keeps us on the ground and gives weight to objects. Without gravity, objects would not have any weight and would float freely in space.