Force, Work and Energy Quiz

Consider the following situations involving forces acting on objects. Which scenario best illustrates the concept of balanced forces?

1. A heavy box being pushed across the floor with a constant speed.
2. A soccer ball rolling down a hill and gaining speed.
3. A seesaw with equal weights on both sides
4. A cyclist accelerating while riding uphill against the force of gravity.

Answer: (c) A seesaw with equal weights on both sides

In the context of force and its effects, which of the following examples best illustrates how an applied force can cause a temporary change in the shape of an object?

1. A toy car speeding down a ramp after being pushed.
2. A soccer ball rolling across the field after being kicked
3. A heavy book resting on a table without moving.
4. A rubber band stretching when pulled and then returning to its original shape when released.

Answer: (d) A rubber band stretching when pulled and then returning to its original shape when released.

Fill in the blanks: When a force is applied to a spring, it causes the spring to __________ and store __________ energy.

1. expand, potential
2. stretch, kinetical
3. compress, kinetic
4. compress, potential

Answer: (d) compress, potential

Which of the following statements accurately describes sound energy?

1. Sound energy travels faster in a vacuum than in water.
2. Sound waves do not require a medium to travel.
3. Sound energy can be seen, but not heard.
4. Sound is produced by vibrations of particles in a medium.

Answer: (d) Sound is produced by vibrations of particles in a medium.

Two children are pushing a box from opposite sides with equal force of 500 N. One pushes from the left and the other from the right. What will most likely happen to the box?

1. The net force is 0 N, and the box will stay in place.
2. The net force is 1000 N, and the box will move in the direction of B.
3. The net force is 1000 N, and the box will stay in place.
4. The net force is 500 N, and the box will move in the direction of A.

Answer: (a) The net force is 0 N, and the box will stay in place.

Which of the following scenarios best illustrates the effect of friction in stopping motion?

1. A ball rolling down a hill
2. A person sliding down a slide
3. Applying breaks to a moving car
4. A book falling off a table

Answer: (c) Applying breaks to a moving car

A rock is held at the edge of a cliff. If the rock is released and falls to the ground, which of the following statements best describes the energy transformation that occurs?

1. The rock’s gravitational potential energy is converted into kinetic energy as it falls.
2. The rock's kinetic energy is transformed into thermal energy, causing the rock to heat up.
3. The gravitational energy remains constant while the rock is falling.
4. The rock loses all of its energy upon hitting the ground, and no energy transformation occurs.

Answer: (a) The rock’s gravitational potential energy is converted into kinetic energy as it falls.

In a wind turbine, mechanical energy from the wind is used to generate electricity. If the wind speed decreases significantly, what would most likely happen to the amount of electrical energy produced?

1. The electrical energy produced would increase as the turbine slows down.
2. The electrical energy produced would decrease because less mechanical energy is available.
3. The electrical energy produced would stay the same, as turbines are designed to work with any wind speed.
4. The electrical energy produced would increase because slower winds are more efficient.

Answer: (b) The electrical energy produced would decrease because less mechanical energy is available.

A group of students is participating in a science project where they need to design a vehicle that can travel the fastest on a flat surface. After discussing the principles of friction, they decide to use different materials for the wheels. Which of the following choices would be the most effective for minimising friction to achieve greater speed, and why?

1. Rubber wheels
2. Plastic wheels
3. Wooden wheels
4. Iron wheels

Answer: (b) Plastic wheels

Two vacationers walk out on a horizontal pier at a constant speed as shown in the diagram below. As they approach the end of the pier, what happens to their gravitational potential energy and kinetic energy? Choose the correct option from the table.

1. A
2. B
3. C
4. D

Answer: (c) C