Further mechanics Flashcards
1
Q
What makes a collision elastic?
A
When both the KE and momentum are conserved.
2
Q
What makes a collision inelastic?
A
When only the momentum is conserved but some of the KE is converted into other types of energy.
3
Q
What is the law of conservation of momentum?
A
The momentum before and after a collision is always the same unless there has been an external force applied.
4
Q
Derive the impulse equation. FΔt=Δ(mv).
A
F=ma, a=Δv/Δt
F=Δv/Δt x m
F=Δ(mv)/Δt
FΔt=Δ(mv)
5
Q
When CANNOT the equation Ek=p^2/2m be used?
A
On a relativistic particle
6
Q
Derive the equation Ek=p^2/2m
A
Ek=1/2 mv^2, p=mv
2Ek/m=v^2
v^2=(p/m)^2
p^2 m/m^2 x 1/2=Ek
Ek=p^2/2m
7
Q
A
