Work-Energy Theorem

Front

What is the Work-Energy Theorem?

Back

The Work-Energy Theorem states that the net work done on an object is equal to the change in its kinetic energy.

Front

Define kinetic energy (KE).

Back

Kinetic energy is the energy an object possesses due to its motion, calculated as KE = 1/2 mv², where m is mass and v is velocity.

Front

What happens to kinetic energy when velocity is doubled?

Back

When velocity is doubled, kinetic energy increases by a factor of four (4) because KE is proportional to the square of velocity.

Front

Calculate the work done if a force of 50 N moves an object 3 m.

Back

Work = Force × Distance = 50 N × 3 m = 150 J.

Front

What is the formula for calculating work done?

Back

Work (W) is calculated using the formula W = F × d × cos(θ), where F is the force, d is the distance, and θ is the angle between the force and the direction of motion.

Front

If a car accelerates from rest to a speed of 20 m/s, what is its change in kinetic energy?

Back

Change in KE = 1/2 m(vf² - vi²). For a 1000 kg car, KE = 1/2 × 1000 kg × (20 m/s)² = 200,000 J.

Front

What is the relationship between work and energy?

Back

Work is a transfer of energy; when work is done on an object, energy is transferred to that object.

Front

True or False: Work can be done on an object even if it does not move.

Back

False. Work requires movement in the direction of the force applied.

Front

What is the unit of work in the International System of Units (SI)?

Back

The unit of work is the Joule (J).

Front

How does mass affect kinetic energy?

Back

Kinetic energy is directly proportional to mass; increasing mass increases kinetic energy if velocity remains constant.