In a ballistic pendulum experiment, a small marble is fired into a cup attached
ID: 1469040 • Letter: I
Question
In a ballistic pendulum experiment, a small marble is fired into a cup attached to the end of a pendulum. If the mass of the marble is 0.0265 kg and the mass of the pendulum is 0.250 kg, how high will the pendulum swing if the marble has an initial speed of 5.85 m/s? Assume that the mass of the pendulum is concentrated at its end so that linear momentum is conserved during this collision.
Hint: When two objects combine into one object during a collision, this is called an inelastic collision. What is conserved in an inelastic collision?
Explanation / Answer
by conservation of momentum
initial momentum = final momentum
0.0265 * 5.85 = (0.0265 + 0.25) * v
v = 0.56067 m
by conservation of energy
initial energy = final energy
0.5 * mv^2 = mgh
0.5 * v^2 = gh
0.5 * 0.56067 ^2 = 9.8 * h
h = 0.01603 m
height the pendulum will reach = 0.01603 m
during inelastic collision momentum is conserved