1.
Which tools are needed to measure the speed of a rolling soccer ball?
Correct Answer
D. Stopwatch, ruler
Explanation
To measure the speed of a rolling soccer ball, a stopwatch and a ruler are needed. A stopwatch is used to measure the time it takes for the ball to travel a certain distance, while a ruler is used to measure the distance traveled by the ball. By dividing the distance by the time, the speed of the rolling soccer ball can be calculated.
2.
Which of the following is most likely to increase friction?
Correct Answer
A. Grooved rubber soles on shoes
Explanation
Grooved rubber soles on shoes are most likely to increase friction because the grooves provide more surface area for contact with the ground. This increased surface area creates more friction between the shoe and the ground, making it harder for the shoe to slide or slip.
3.
The force that pulls objects to the ground on Earth is known as__.
Correct Answer
D. Gravity
Explanation
Gravity is the force that pulls objects towards the ground on Earth. It is a fundamental force of nature that is responsible for the attraction between objects with mass. Unlike magnetism, which involves the interaction of magnetic fields, gravity is a force that acts on all objects, regardless of their magnetic properties. Collision and friction are not forces that specifically pull objects towards the ground, making them incorrect answers.
4.
Which of the following is not a contact force?
Correct Answer
C. Magnetism
Explanation
Magnetism is a non-contact force because it can exert a force on objects without physical contact. Unlike collision and friction, which require direct contact between objects to exert a force, magnetism can attract or repel objects from a distance without any physical touch. This is due to the magnetic field that surrounds magnets and can interact with other magnetic objects or materials. Therefore, magnetism is the correct answer as a non-contact force.
5.
Without ___, we would not be able to walk or climb stairs.
Correct Answer
C. Friction
Explanation
Friction is the force that opposes the motion of objects in contact with each other. Without friction, there would be no resistance between our feet and the ground, making it impossible to walk or climb stairs. Friction allows us to have traction and grip on surfaces, preventing us from slipping or sliding. It is the essential force that enables us to have control and stability while moving on solid ground.
6.
A push or a pull on an object is:
Correct Answer
A. A force
Explanation
A push or a pull on an object is considered a force because a force is defined as any interaction that can change the motion or shape of an object. When an object experiences a push or a pull, it is being acted upon by a force that can cause it to accelerate, decelerate, or change direction. Therefore, the correct answer is a force.
7.
Forces can change the:
Correct Answer
C. Movement of objects but only if they were already in motion
Explanation
Forces can accelerate objects, decelerate them (slowing down), or change their direction of motion. However, forces do not directly change the mass of an object. Mass is a measure of the amount of matter in an object and remains constant unless additional matter is added or removed from the object. Forces can affect the motion of objects regardless of whether they were initially at rest or in motion.
8.
Objects that have balanced forces acting upon them are
Correct Answer
D. Non-accelerating
Explanation
When the forces acting on an object are balanced, the net force is zero. This means there is no acceleration, as acceleration occurs only when there is a net force acting on an object according to Newton's Second Law of Motion. The object might still be moving, but if it is, it does so at a constant velocity.
9.
Sir Isaac Newton stated that for every action, there was:
Correct Answer
A. An equal and opposite reaction
Explanation
Sir Isaac Newton's third law of motion states that for every action, there is an equal and opposite reaction. This means that whenever 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 explains the fundamental principle of how forces interact in the physical world and is applicable in various scenarios, such as the recoil of a gun when fired or the propulsion of a rocket.
10.
The size or magnitude of a frictional force depends on:
Correct Answer
C. Both of the above
Explanation
The size or magnitude of a frictional force depends on both the forces pushing the surfaces together and the roughness of the contact surfaces. When two surfaces are pressed together with a greater force, the frictional force between them also increases. Additionally, the rougher the surfaces are, the stronger the frictional force becomes. Therefore, both factors play a role in determining the size or magnitude of a frictional force.