In a blaistic pendulum, a spring gun, with spring constant k, is aimed horizonta
ID: 1989109 • Letter: I
Question
In a blaistic pendulum, a spring gun, with spring constant k, is aimed horizontally releasing a spring that has been compressed a distance x. a ball of mass m is fired at the bob of a pendulum. the bob has a mass M, and is suspended by a rod of negligible mass. after the collision, the ball stays inside the cup of the bob and swings through the arc, eventually ganing a hieght h. (a) find the hight in terms of the given veriables. (b) if a 2.50g bullet is firedinto a balstic pendulum whose bob has a mass od 0.500kg, determine the intial speed vo that would cause the bob to rise to a height of 0.100m.
Explanation / Answer
0.5 k x^2 = 1/2 m v^2
so v=sqrt(k/m)*x
by momentum conservation
mv+0=(m+M)v'
v'=mv/(M+m)
energy conservation
(M+m)gh= 0.5 ( m+M)v'^2
h=0.5 m^2 * v^2 /((M+m)^2 *g)
h=mkx2/((M+m)2 *g)-------------ans
2)use h=0.5 m^2 * v^2 /((M+m)^2 *g)
substitute all given values to get answer