Energy Basics
What is the ability to do work?
Energy
This form of energy comes from moving electrons?
Electrical energy
What is the formula for work?
force × distance
What is the formula for power?
work ÷ time
Lifting a book is an example of what kind of work?
positive work
What is the unit of measuring energy?
Joules (J)
Stored energy in food is an example of what form of energy?
Chemical
What are the units of work?
Joules (J)
What is unit of measuring power called?
Watt (W)
If you carry a heavy box across a room at a constant height, is work done?
no (no vertical displacement)
What are the two main types of energy?
Potential & Kinetic
The energy stored due to an object’s height is called...
Potential energy
If no movement happens, how much work is done?
zero
A person does 100 J of work in 5 seconds. What is their power output?
20 W
Running up stairs faster increases which one: work or power?
power
What is the energy of motion called?
Kinetic
A stretched rubber band is an example of what type of energy?
Potential energy
A student pushes a cart with 20 N for 3 m. How much work is done?
60 J
If two people do the same work, but one is faster, who is more powerful?
the faster one
A battery powering a flashlight transforms chemical energy into what form?
light (or electrical) energy
What law states that energy cannot be created or destroyed?
Law of Conservation of Energy
Energy from the sun is also called ...
Solar energy
What factor must be in the same direction as the displacement for work to be done.
force
One horsepower is equal to how many watts (rounded)?
746 watts
Why is it easier to lift a box with a ramp?
Because the ramp reduces the force needed by increasing distance (mechanical advantage).