What is work?
Work is done when a force moves an object through a distance in the direction of the force.
Write the formula for calculating work done.
\( W = F \times D \)
What is the formula for work done in lifting an object?
\( W = mgh \)
How do you calculate work when force is at an angle?
\( W = F \cos \theta \times D \)
Define energy.
Energy is the capacity to do work. It is a scalar quantity measured in joules (J).
What is potential energy?
Stored energy due to an object’s position or state.
Write the formula for potential energy.
\( E_p = mgh \)
What is kinetic energy?
Energy possessed by a moving object due to its motion.
Write the formula for kinetic energy.
\( E_k = \frac{1}{2}mv^2 \)
What is power?
Power is the rate at which work is done or energy is transferred.
State the formula for power.
\( P = \frac{W}{t} \)
State an alternate formula for power involving force and velocity.
\( P = F \times v \)
What is the unit of power?
The watt (W).
State the law of conservation of energy.
Energy cannot be created or destroyed, only transformed from one form to another.
Give an example of mechanical energy conversion.
In a generator, mechanical energy is converted to electrical energy.
List three types of mechanical energy.
Potential energy, kinetic energy, and elastic energy.
What are renewable energy sources?
Energy sources that can be replenished naturally, such as solar and wind energy.
What are non-renewable energy sources?
Energy sources that cannot be replaced once used, like petroleum and coal.
Give an example of energy transformation in an electric iron.
Electrical energy is converted into heat energy.
What is the relationship between energy and work?
Energy is the capacity to do work; both are measured in joules.
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