# data[].attributes.body
a form of energy that comes

from force applied over distance. A force of 1 newton does 1 joule of work when the force causes 1 meter of motion in the direction of the force.

# data[].attributes.body
Work done against gravity is equal to weight multiplied by the change in height

# data[].attributes.body
Work input :the work that is done

on an object.

Work Output :the work that an

object does as a result of work input.

# data[].attributes.body
Energy drives all the processes in nature, from winds in the atmosphere to nuclear reactions occurring in the cores of stars. In the environment, efficiency is

interpreted as the fraction of incoming energy that goes into a process. For example, Earth receives energy from the sun. Earth absorbs this solar energy

with an average efficiency of 78 percent. The energy that is not absorbed is reflected back into space.

# data[].attributes.body
Recall that energy is always needed to do work. An object that has energy is able to do work; without energy, it is impossible to do work. The more energy you have, the more work you can do. For example, a ball rolling across a table has kinetic energy that can be used to do work. If the ball collides with a toy car, it will do work on the car and change its motion. Some of the ball’s kinetic energy is transferred to the car. Collision is a common method of doing work.

# data[].attributes.body
The ratio of usableoutput work divided by total input work. Efficiency is often expressed as a percent, with a perfect machine having 100 percent efficiency

# data[].attributes.body
The energy output of a process or machine can never exceed the energy input.

# data[].attributes.body
power :the rate of doing work or moving energy. Power is equal to energy (or work) divided by time.

watt (W) :a unit of power equal to 1 joule per second.

horsepower (hp) :a unit of power equal to 746 watts.