Question
For shooting practice a person uses a pellet gun and an empty pop can. The pop can rests on a flat surface that has a coefficient of kinetic friction 0.500. The pellet has a mass of 0.140 kg and the pop can has a mass of 0.470 kg. After the pellet is fired and now inside the pop can they slide together for 6.80 m. What was the speed of the pellet?
Answers
Damon
total mass = .14 +.47 = .61 kg
weight = .61*9.81
friction force = .5 * .61 * 9.81
work done = force * distance = .5*.61*9.81*6.8
so
(1/2)(.61) v^2 = .5 * .61 * 9.81*6.8
where v is initial speed of can with pellet
v^2 = 9.81*6.8
solve for v
now conservation of momentum
u is pellet speed
.14 u = .61 v
weight = .61*9.81
friction force = .5 * .61 * 9.81
work done = force * distance = .5*.61*9.81*6.8
so
(1/2)(.61) v^2 = .5 * .61 * 9.81*6.8
where v is initial speed of can with pellet
v^2 = 9.81*6.8
solve for v
now conservation of momentum
u is pellet speed
.14 u = .61 v