Conservation Laws Flashcards
1
Q
When is Mechanical Energy Conserved?
A
When there is no net work done by external forces (and when there is no internal energy conversion)
2
Q
When is angular momentum conserved?
A
when no net external torque acts
3
Q
When is momentum in a direction conserved?
A
when no net external force acts in that direction.
4
Q
Momentum is equal to
A
mass times velocity (p=mv)
5
Q
Standard units of momentum are
A
newton-seconds or N-s (can be Kg-m/s)
6
Q
What is the direction of an object’s momentum?
A
the same as its direction of motion.
7
Q
What is Impulse equal to?
A
change in an object’s momentum (J=deltap)
or Force x time
8
Q
Impulse can also equal…
A
Force x time of collision (J=Ft)
9
Q
The impulse-momentum theorem is…
A
Force applied x time of collision = delta (mass x velocity)
Ft=delta(mv)
