Physics Terms
What is energy?
The ability to work.
The formula for calculating work.
W = Fd
What is power?
Rate of doing work
How much work is done on a object that has a force of 18 N applied to it and it moves 5.0 m in the direction of the force?
90 Joules
A force of 10 N is applied to an object at an angle of 60 degrees above the horizontal. The object is moved 5.0 m. Find the work done on the object.
25 joules
Two types of mechanical energy
Kinetic and potential
Formula for kinetic energy
Ek = 1/2 mv2
What in the SI unit of power?
Watt
Calculate the kinetic energy of a ball with a mass of .50 kg that is moving at 6.0 m/s.
9.0 Joules
A rock with a mass of 10 kg is dropped from a height of 12 m. What is it potential energy when it is 2.0 m high? What is its kinetic energy?
potential is 196 J
kinetic is 980 J
Energy of an object in motion
kinetic energy
Formula for gravitational potential energy.
Ep = mgh
Basic Formula for calculating power
P = W/t
Calculate the potential energy of a rock with a mass of 10 kg that is raised 5.0 m above the surface of the earth.
490 Joules
A force of 10 N is applied to an object causing it to accelerate and reach a velocity of 5.0 m/s. Find the power out of the force.
50 Watts
Two types of potential energy.
Gravitation and elastic
Formula for elastic potential energy.
Epe = 1/2 k x2
Alternate formula for calculating power
P = Fv
Calculate the elastic potential energy stored in a spring whose force constant is 10 N/m when it is stretched 2.0 m.
20 Joules
A mass of 10 Kg is attached to a spring with a force constant of 5.0 N/m, and dropped so that it stretches the spring .20 meters. If the mass is moving at .10 m/s, find the total energy of the system.
.15 joules
The rate of doing work.
Power
Work-Kinetic Energy Formula
Wnet = change in Ek
An object with a mass of 2.0 kilograms is raised 3.0 meters in 10 seconds by a person. Find the power exerted by the person.
5.9 watts
Calculate the velocity of a rock that falls from a height of 10 m, just before it hits the ground.
14 m/s
Easy daily question: Who is your Physics teacher?
Mr. Sauber (RAS)