In a ballistic pendulum experiment, a small marble is fired into a cup attached
ID: 2265361 • 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 0.0225 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 5.65 m/s? Assume that the mass of the pendulum is concentrated at its end.
Its not 6.51m because the velocity of the marble and the cup is different from the initial velocity of the marble. And its not .134m because an inelasitc collision energy is not conserved. At least that's what the website told me when I tried.
Explanation / Answer
using momentum conservation,
0.0225 x 5.65 + 0 = (0.0225 + 0.250)v
v = 0.467 m/s
using energy conservation,
mv^2 /2 = mgh
h = v^2 /2g = 0.467^2 / 2x9.8 = 0.0111 m or 1.11 cm