Question

work, energy, and power

1. what is the definition of work in physics?
2. how is energy related to work?
3. what is the formula for calculating work?
4. what are the units of work?

Explanation:

1. In physics, work is defined as the transfer of energy that occurs when a force is applied to an object and the object moves in the direction of the force.
2. Energy is the ability to do work. Work done on an object can change its energy (kinetic, potential etc.). They are closely related as work - energy theorem states work done on a system is equal to the change in its energy.
3. The formula for calculating work when a constant force $F$ acts on an object and it moves a displacement $d$ in the direction of the force is $W = F\times d$. When the force and displacement are at an angle $\theta$, the formula is $W = Fd\cos\theta$.
4. The SI unit of work is the joule (J). It is the same as the unit of energy since work is a transfer of energy.

Answer:

1. Work is the transfer of energy that occurs when a force causes an object to move in the direction of the force.
2. Energy is the ability to do work, and work done on an object can change its energy state.
3. $W = Fd$ (for force and displacement in same direction), $W = Fd\cos\theta$ (for force and displacement at an angle $\theta$).
4. The SI unit of work is the joule (J).