Work
if an object is not accelerating, the change in KE is _____.
0
Gravitational potential energy is the energy due to ____
position
When is mechanical energy conserved?
when there is no friction, etc.
What are the base units of power?
kg⋅m2⋅s−3
If the sign of work is negative, this means that .....
force and displacement are in opposite directions. Example: friction
The work done lifting an object is _____ its change in potential energy.
equal to
If a job done two different ways requires the same amount of work, how is power affected?
depends on the time
A car slows down on a flat road. What type of is work being done and by which force?
Possible answers:
negative work by friction. negative work by air resistance
Ball A has double the mass of ball B. What is the ratio of KE of A to B?
2:1
What are the base units for a spring constant?
kg.s-2
The distance an object is pushed doubles while the time it takes to do the work is cut in half, what happens to the power?
4 times greater
What are the base units of work?
Kg.m^2/s^2
If the power an object has triples what will happen to its speed
it will triple
If a newer better engine has twice the power of an older engine, this means that, in terms of work, the newer engine can do what?
twice the work in the same amount of time; same work in half the time
The work required to bring an object up to a final speed from rest is called what?
Kinetic energy
if the length of a stretched spring is is cut in half, its elastic potential energy would be _________
1/4
What is a dissipative force? Define and give one example.
A dissipative force is a non-conservative force that decreases the mechanical energy in a system (converts KE and PE into other forms of energy). Ex: friction, air resistance,etc.