5470: Work & Power

Front

What is Power in physics?

Back

Power is the rate at which work is done or energy is transferred over time. It is measured in watts (W).

Front

How can power output be increased?

Back

Power output can be increased by decreasing the amount of time in which work is done.

Front

What is Work in physics?

Back

Work is defined as the product of the force applied to an object and the distance over which that force is applied, in the direction of the force. It is measured in joules (J).

Front

What is the formula for calculating Work?

Back

Work (W) = Force (F) × Distance (d) × cos(θ), where θ is the angle between the force and the direction of motion.

Front

What does a negative value of work indicate?

Back

A negative value of work indicates that the force applied is acting in the opposite direction to the displacement of the object.

Front

Which force does no work when an object moves horizontally?

Back

The normal force (Fn) does no work when an object moves horizontally, as it acts perpendicular to the direction of motion.

Front

What is the relationship between work and energy?

Back

Work done on an object results in a change in its energy. The work-energy principle states that the work done is equal to the change in kinetic energy.

Front

What is Kinetic Energy?

Back

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

Front

What is the significance of net work?

Back

Net work is the total work done on an object, which determines the change in its kinetic energy.

Front

What happens to total mechanical energy when negative work is done?

Back

When negative work is done, the total mechanical energy of the system decreases.