1.
Write your text here
2.
Write your text here
3.
What energy is present in moving object?
Correct Answer
C. Kinetic Energy
Explanation
Kinetic energy is the energy possessed by an object due to its motion. When an object moves, it has the ability to do work and transfer energy to other objects or systems. This energy is known as kinetic energy. It depends on the mass and velocity of the object. The faster an object moves or the heavier it is, the more kinetic energy it possesses. Therefore, kinetic energy is the correct answer for the energy present in a moving object.
4.
What form of energy is stored in the leaves of plants?
Correct Answer
A. Chemical Energy
Explanation
Plants store energy in the form of chemical energy. This energy is obtained through the process of photosynthesis, where plants convert sunlight into glucose and other organic compounds. These compounds are then stored in the leaves as starch or other forms of carbohydrates. When needed, the plant can break down these compounds to release the stored energy for various metabolic processes. Therefore, the correct answer is chemical energy.
5.
3. Which of the following statement is true?
Correct Answer
D. An object in motion will remain in motion
Explanation
This statement is based on Newton's first law of motion, also known as the law of inertia. According to this law, an object in motion will continue to move in a straight line at a constant speed unless acted upon by an external force. This means that if no force is applied to an object in motion, it will continue to move indefinitely.
6.
In which part of the magnet are magnetic forces strongest?
Correct Answer
C. At its north pole
Explanation
The magnetic forces are strongest at the north pole of a magnet. This is because the north pole of a magnet attracts the south pole of another magnet, and opposite poles attract each other with the strongest force. Therefore, the north pole of a magnet has the strongest magnetic force.
7.
Which situation does not show the transformation of potential energy to kinetic energy?
Correct Answer
B. During a baseball game, a good outfield caught a flying ball.
8.
13. A baseball and a sheet of paper are dropped at the same time from the same height. What will occur if there is no air resistance?
Correct Answer
D. The baseball and the paper will land at the same time
Explanation
If there is no air resistance, both the baseball and the sheet of paper will experience the same acceleration due to gravity. This means that they will fall at the same rate and will therefore land at the same time. The mass of the objects does not affect their rate of fall in the absence of air resistance.
9.
A boy sits on a grassy slope. What force stops him from sliding down?
Correct Answer
A. Friction
Explanation
Friction is the force that stops the boy from sliding down the grassy slope. When the boy sits on the slope, the friction between his body and the grass provides a counteracting force against the downward pull of gravity. This frictional force acts in the opposite direction to the sliding motion, preventing the boy from moving down the slope. Without friction, the boy would slide down due to the force of gravity.
10.
The boat sailing on the sea slows down. What kind of friction is acting on it?
Correct Answer
D. Fluid Friction
Explanation
When a boat is sailing on the sea, it experiences fluid friction. Fluid friction, also known as drag, is the resistance that occurs when an object moves through a fluid, such as air or water. In this case, as the boat moves through the water, the water molecules exert a force on the boat, causing it to slow down. This force of fluid friction opposes the motion of the boat and is responsible for its deceleration.
11.
SHOVELS
Correct Answer
C. Third Class Lever
Explanation
Shovels are an example of a third class lever because the effort (force applied by the person using the shovel) is located between the fulcrum (the point where the shovel pivots) and the load (the dirt being lifted). In a third class lever, the effort arm is shorter than the load arm, which means that a greater effort force is required to move the load.
12.
Nutcraker
Correct Answer
B. Second Class Lever
Explanation
A nutcracker is a device used to crack open nuts. It typically consists of two handles joined together at one end and a hinge at the other end. When pressure is applied to the handles, the hinge acts as a fulcrum, allowing the force to be concentrated at the point where the nut is being cracked. In a second class lever, the load is located between the fulcrum and the effort. In the case of a nutcracker, the nut serves as the load, the hinge acts as the fulcrum, and the force applied to the handles is the effort. Therefore, a nutcracker is an example of a second class lever.
13.
Spade
Correct Answer
A. First Class Lever
Explanation
A spade is a tool that consists of a long handle and a flat blade. In the context of levers, a first-class lever is a type of lever where the fulcrum is positioned between the effort and the load. In this lever, the handle of the spade acts as the lever arm, the point where the handle is attached to the blade acts as the fulcrum, and the load is the soil or material being lifted. Therefore, a spade can be considered as an example of a first-class lever.
14.
Rake
Correct Answer
C. Third Class Lever
Explanation
A rake is an example of a third-class lever because the effort is applied between the fulcrum (the point where the rake rests on the ground) and the load (the leaves or debris being gathered). In a third-class lever, the effort arm is shorter than the load arm, meaning that a greater effort force is required to move the load.
15.
Wheelbarrow
Correct Answer
B. Second Class Lever
Explanation
A wheelbarrow is an example of a second-class lever because the load (the weight being carried) is located between the fulcrum (the wheel) and the effort (the person pushing or pulling the handles). In a second-class lever, the load is closer to the fulcrum than the effort, which allows for a mechanical advantage. This means that less effort is required to lift or move a heavy load, making it easier for the person using the wheelbarrow.
16.
Can opener
Correct Answer
B. Second Class Lever
Explanation
A can opener is an example of a second-class lever because the load (the can lid) is between the fulcrum (the point where the can opener pivots) and the effort (the force applied by the user). In a second-class lever, the load is always closer to the fulcrum than the effort, which allows for greater mechanical advantage. In the case of a can opener, the user applies force at the handle (the effort) to lift the lid (the load) using the pivot point (the fulcrum) as a support.
17.
Scissors
Correct Answer
A. First Class Lever
18.
Tweezers
Correct Answer
C. Third Class Lever
Explanation
A lever is a simple machine that consists of a rigid bar that rotates around a fixed point called a fulcrum. In a third class lever, the fulcrum is located at one end of the lever, the effort is applied at the other end, and the load is located between the fulcrum and the effort. This means that the load is closer to the fulcrum than the effort, resulting in a mechanical advantage less than 1. In the case of tweezers, the fulcrum is the pivot point where the two arms meet, the effort is applied by squeezing the handles, and the load is the object being grasped. Therefore, tweezers can be classified as a third class lever.
19.
Spoon
Correct Answer
C. Third Class Lever
Explanation
A third-class lever is a type of lever where the effort is applied between the fulcrum and the load. In the case of a spoon, the fulcrum is the point where the spoon rests on a surface, the load is the food being lifted, and the effort is applied by the hand holding the spoon. This arrangement allows for a greater range of motion and speed, making it easier to scoop up food with a spoon. Therefore, a spoon can be considered as an example of a third-class lever.
20.
Baseball bat
Correct Answer
C. Third Class Lever
Explanation
A baseball bat is an example of a third-class lever because the effort (force applied by the batter) is located between the fulcrum (the batter's hands) and the load (the ball). In this case, the effort is the force exerted by the batter to swing the bat, the fulcrum is the batter's hands gripping the bat, and the load is the ball being hit. Third-class levers are designed to increase speed and range of motion, but at the expense of force.
21.
Broom
Correct Answer
A. First Class Lever
Explanation
A broom is an example of a first-class lever because the fulcrum (pivot point) is located between the effort (force applied to the handle) and the load (the weight being lifted or moved). In the case of a broom, the handle acts as the lever arm, the fulcrum is where the handle connects to the broom head, and the load is the weight of the dirt or debris being swept. By applying force to the handle, the broom can lift or move the load.
22.
Crowbar
Correct Answer
A. First Class Lever
Explanation
A crowbar is an example of a first-class lever because the fulcrum is located between the effort and the load. In a first-class lever, the effort is applied on one side of the fulcrum and the load is on the other side, with the fulcrum in the middle. This allows the crowbar to exert a large amount of force on an object by applying a smaller effort over a greater distance.
23.
seesaw
Correct Answer
A. First Class Lever
Explanation
A seesaw is an example of a first-class lever because the fulcrum is located between the effort and the load. In a first-class lever, the effort is applied on one side of the fulcrum and the load is on the other side, with the fulcrum acting as the pivot point. This arrangement allows for the amplification or reduction of force depending on the distance of the effort and load from the fulcrum. In the case of a seesaw, the effort is applied by pushing down on one end, causing the other end to rise and lift the load.
24.
fishing pole
Correct Answer
C. Third Class Lever
Explanation
A fishing pole is an example of a third-class lever because the effort (force) is applied between the fulcrum (pivot point) and the load (fish). In this case, the effort is the force exerted by the angler to lift and catch the fish, the fulcrum is the point where the pole is held or rests, and the load is the weight of the fish. Third-class levers are characterized by having the effort closer to the fulcrum than the load, resulting in an increase in speed and range of motion, but a decrease in force.
25.
pliers
Correct Answer
A. First Class Lever
Explanation
Pliers are an example of a first-class lever because the fulcrum (pivot point) is located between the effort (force applied) and the load (object being lifted or moved). In the case of pliers, the fulcrum is the joint where the two handles meet, the effort is applied by squeezing the handles together, and the load is the object being gripped by the jaws of the pliers.
26.
All objects fall toward the ____________ of the Earth.
Correct Answer
B. Center
Explanation
All objects fall toward the center of the Earth due to gravity. Gravity is the force that pulls objects toward each other, and on Earth, it pulls everything toward its center. This is why objects always fall downward when dropped or released, as gravity is constantly pulling them toward the Earth's center.
27.
All objects are attracted to each other because of ____________.
Correct Answer
A. Gravity
Explanation
Gravity is the force of attraction between all objects with mass. It is responsible for the motion of planets, the formation of galaxies, and the falling of objects on Earth. Gravity is a fundamental force in the universe that causes objects to be pulled towards each other. It is the reason why objects fall to the ground when dropped and why planets orbit around the sun.
28.
The farther you are from Earth, the ____________ your weight.
Correct Answer
D. Lesser
Explanation
As you move farther away from Earth, the force of gravity decreases. This means that your weight, which is the measure of the force of gravity acting on your body, will also decrease. Therefore, the correct answer is "lesser".
29.
The gravity between two objects decreases as the distance between them ____________.
Correct Answer
C. Increases
Explanation
The gravity between two objects decreases as the distance between them increases. This is because gravity is an attractive force that weakens with distance. As the objects move farther apart, the gravitational pull between them becomes weaker, resulting in a decrease in gravity.
30.
The more distant the body from Earth, the ____________ gravitational force of attraction.
Correct Answer
E. Higher
Explanation
As the distance between two objects increases, the gravitational force of attraction between them decreases. Therefore, the correct answer is "lesser".
31.
Energy can neither be ____________nor ____________. It is only transformed from one form to another; the total amount of energy never changes.
Correct Answer
A. Created, destroyed
Explanation
Energy can neither be created nor destroyed. This is known as the law of conservation of energy. It states that energy can only be transformed from one form to another, but the total amount of energy in a closed system remains constant. This principle is fundamental in understanding the behavior and interactions of energy in various systems.
32.
Falling objects on Earth pass through air.
Correct Answer
A. True
Explanation
Objects falling on Earth do pass through air. When an object falls, it experiences air resistance, which is the force exerted by the air on the object as it moves through it. This resistance opposes the motion of the object and causes it to slow down. The amount of air resistance depends on factors such as the size, shape, and speed of the object. Therefore, it is true that falling objects on Earth pass through air.
33.
What goes down, comes up
Correct Answer
B. False
Explanation
The statement "What goes down, comes up" implies that something that goes down will eventually come back up. However, this statement is not always true. There are many instances where something that goes down may not come back up. Therefore, the correct answer is False.
34.
The speed of falling objects will be the same on Earth and on the moon.
Correct Answer
B. False
Explanation
The speed of falling objects will not be the same on Earth and on the moon because the acceleration due to gravity is different on each celestial body. On Earth, the acceleration due to gravity is approximately 9.8 m/s^2, while on the moon it is only about 1.6 m/s^2. This means that objects will fall slower on the moon compared to Earth. Therefore, the statement is false.
35.
If you drop the feather and the hammer on the moon, the hammer and the feather will fall at the same speed.
Correct Answer
A. True
Explanation
In the absence of an atmosphere on the moon, there is no air resistance to slow down the fall of objects. Therefore, both the feather and the hammer will experience the same acceleration due to gravity and fall at the same speed. This phenomenon is known as the equivalence principle and was famously demonstrated by astronaut David Scott during the Apollo 15 mission in 1971.
36.
Friction opposes motion
Correct Answer
A. True
Explanation
Friction is a force that acts in the opposite direction of motion, making it harder for objects to move. This resistance is due to the interaction between the surfaces of two objects in contact. When an object is in motion, friction acts in the direction opposite to its motion, effectively opposing its movement. Therefore, the statement "Friction opposes motion" is true.
37.
Stationary friction occurs in moving objects.
Correct Answer
B. False
Explanation
Stationary friction occurs when an object is at rest or not moving. It is the force that opposes the motion of an object when an external force is applied to it. Therefore, stationary friction does not occur in moving objects.
38.
Friction converts some energy into heat and causes wear and tear on materials.
Correct Answer
A. True
Explanation
Friction is a force that opposes the motion of objects in contact with each other. When objects rub against each other, the friction between them converts some of the energy into heat. This heat generation is why we feel objects getting warm when we rub them together. Additionally, friction can also cause wear and tear on materials as the surfaces rub against each other, leading to the gradual degradation of the materials over time. Therefore, the statement that friction converts energy into heat and causes wear and tear on materials is true.
39.
Sound energy is produced by vibrating objects
Correct Answer
A. True
Explanation
Sound energy is produced by vibrating objects. When an object vibrates, it creates waves of pressure in the surrounding medium, such as air or water. These pressure waves then travel through the medium as sound energy. This is why we can hear sounds when an object vibrates, such as when a guitar string is plucked or when a drum is struck. Therefore, the statement "Sound energy is produced by vibrating objects" is true.
40.
Mechanical energy is the energy possessed by a moving object due to its motion or its stored energy of position.
Correct Answer
A. True
Explanation
Mechanical energy refers to the energy associated with the motion or position of an object. When an object is moving, it possesses kinetic energy, and when it is at rest, it possesses potential energy. Therefore, it is true that mechanical energy is the energy possessed by a moving object due to its motion or its stored energy of position.
41.
All potential energy can be changed to kinetic energy
Correct Answer
A. True
Explanation
This statement is true because potential energy is the energy that an object possesses due to its position or condition. When this potential energy is released or converted, it can be transformed into kinetic energy, which is the energy of motion. Therefore, all potential energy can indeed be changed into kinetic energy.
42.
It is the ability or power to do work
Correct Answer
B. Energy
Explanation
Energy is the correct answer because it is the ability or power to do work. Energy is a fundamental concept in physics and is defined as the capacity to cause change or perform work. It can exist in different forms such as kinetic energy, potential energy, thermal energy, and so on. In this context, energy is the most appropriate choice as it directly relates to the ability to do work.