Unit 1 Test Prep: Part 2

Front

Work is only done on an object if the force applied causes __________.

Back

Displacement

Front

Which of the following situations involves positive work being done?

A. A person holds a heavy box without moving it.
B. A car’s brakes bring the car to a stop.
C. A person pushes a cart, and the cart moves forward.
D. A person pulls on a rope tied to a wall.

Back

C. A person pushes a cart, and the cart moves forward.

Front

The stored energy an object has due to its height above a reference point.

Back

Gravitational potential energy

Front

Which of the following affect the kinetic energy of an object? (Select all that apply.)

A. The mass of the object
B. The velocity of the object
C. The height of the object
D. The force applied to the object

Back

A. The mass of the object
B. The velocity of the object

Front

Explain the work-energy theorem.

Back

• The work done on an object is equal to the change in its kinetic energy.

• If positive work is done, the object's kinetic energy increases.

• If negative work is done, the object’s kinetic energy decreases.

Front

Rank the following in order of increasing kinetic energy:

1. 1. A 2-kg ball moving at 3 m/s

2. 2. A 1-kg ball moving at 5 m/s

3. 3. A 3-kg ball moving at 1 m/s

Back

3 < 1 < 2

Front

A book is dropped from a high shelf. Describe the energy transformations that occur as it falls.

What happens next?

Back

• Initially, the book has gravitational potential energy.

• As it falls, the potential energy decreases while kinetic energy increases.

• Just before it hits the ground, most of the energy is kinetic.

• Ignoring air resistance, the total mechanical energy remains constant.

Front

Compare potential energy and kinetic energy. How are they similar, and how are they different?

Back

• Similarities: Both are forms of mechanical energy.

• Differences: Potential energy is stored energy due to position or configuration. Kinetic energy is the energy of motion.

• Both can transform into each other (e.g., falling objects or a pendulum).

Front

What is the unit of work and energy in the SI system?

A. Newton (N)
B. Joule (J)
C. Watt (W)
D. Pascal (Pa)

Back

B. Joule (J)

Front

What concept is often described as 'inertia in motion'?

Back

Momentum