Work
The unit of work
Joules
Energy is the ability to do ________.
Work
Potential Energy + Kinetic Energy = ________
Mechanical Energy
The unit of power is ________.
Watts
Name two examples of nonmechanical energy.
Nuclear, chemical, acoustic, electrical, thermal
When the force and the direction that the object is moving are pointed in opposite directions, work is _______.
negative
Over the course of a ball dropping from 5m, when is the potential energy greatest?
At 5m
Over the course of a ball dropping from 5m, when is the kinetic energy greatest?
Power measures....
The rate at which work is done/the rate of energy transfer
State the Law of Conservation of Energy
Energy cannot be created or destroyed, but changes form.
The amount of work done when the force component is perpendicular to the direction the object moves.
0 Joules
Gravitational potential energy is based on these three factors.
mass, acceleration of gravity, height (displacement from ground level)
The sum of the energies at every point in an objects motion is ________.
constant (the same)
The horsepower is equivalent to nearly ____ Watts.
746
Units composed of a combination of other SI base units are called ______ units.
Derived
The equation for the work-kinetic energy theorem.
W = ∆KE = KE(f) - KE(i)
Potential energy of a spring is based on these two factors.
the spring constant (stiffness of spring) and the distance the spring is compressed or stretched
Ball A and ball B both have a mass of 25kg. If ball A moves 5m/s and ball B moves 10m/s, how much greater is the kinetic energy of ball B?
4 times greater
The amount of work done on an object doubles and the time that it takes to move the object is cut in half. What happens to the power?
It is 4 times greater
Convert 625W to kW.
0.625kW
A mover pushes a 900kg box 18 meters across the floor with a force of 1,540N. How much work is done by the mover on the box?
27,720 J
A person with a mass of 70kg is about to jump off a 62m building with a parachute. What is their potential energy when they first jump (before parachute opens)?
42,575.4 J
At the top of a pendulum swing, the potential energy is 3,450J. At the bottom of the swing, what is the velocity if the mass of the ball is 475kg?
3.811 m/s
A car with a mass of 1120kg is going at a constant speed of 15m/s. The car is pushed forward by a force of 245N. What is the power produced by the engine?
3675 watts
The unit of the spring constant.
N/m