Units
What are the units for energy?
Joules
What must be conserved whenever it is transferred?
Energy
What energy is heat from a campfire?
Thermal energy
A machine does 200 J of work in 10 seconds. What is the power output of the machine?
20 W
A 4 kg baseball is thrown at 20 m/s. Calculate the kinetic energy of the baseball.
1,600 J
What are the units for power?
Watts
What is energy transferred per unit time?
Power
What type of energy is light from the sun?
Electromagnetic energy
A person pushes a cart with a force of 160 N over 2 m in 4 seconds. What power is expended?
80 W
To lift a 40 N crate 5 m takes 20 seconds using a constant upward force. Calculate the power used.
10 W
What are the units for work?
Joules
What is force exerted over a distance?
Work
What type of energy is stored in grass that a cow is about to eat?
Chemical energy
A 2,000 kg roller coaster car is moving at 6 m/s down a track. What is its kinetic energy?
36,000 J
A 50 kg child climbs to the top of a 6 m playground slide. What is the child's gravitational potential energy at the top relative to the ground?
3,000 J
What are the SI units for distance?
Meters
What is the transfer of energy?
Work
What type of energy consists of electrons traveling in a wire?
Electrical energy
A student pushes a box with a force of 20 N over a distance of 4 m in the direction of the force. How much work is done on the box?
80 J
To slide a crate 3 m across a warehouse floor requires 450 J of work. What horizontal force was applied to the crate?
150 N
What are the units for force?
Newtons
What is the ability to do work?
Energy
What type of energy is stored in the nucleus of an atom?
Nuclear energy
A weightlifter does 800 J of work lifting a 200 N barbell. How far did the barbell move upward during the lift?
4 m
A 2 kg book is placed on a shelf 1.5 m above the floor. Calculate the gravitational potential energy gained by the book.
30 J