Blocks A (mass 3.00kg ) and B (mass 14.00kg ) move on a frictionless, horizontal
ID: 1313718 • Letter: B
Question
Blocks A (mass 3.00kg ) and B (mass 14.00kg ) move on a frictionless, horizontal surface. Initially, block B is at rest and block A is moving toward it at 9.00m/s . The blocks are equipped with ideal spring bumpers. The collision is head-on, so all motion before and after the collision is along a straight line. Let +x be the direction of the initial motion of A.
Part A
Find the maximum energy stored in the spring bumpers and the velocity of each block at that time.
Find the maximum energy.
Part B
Find the velocity of A.
Part C
Find the velocity of B.
Part D
Find the velocity of each block after they have moved apart.
Find the velocity of A.
Part E
Find the velocity of B.
Explanation / Answer
A)the collision will be perfectly elastic and the maximum compression will be at a point when they both have the same velcoity.so,
conserving momentum,
3*9=(3+14)*v
or v=1.588 m/s
so energy stored in the springs = 0.5*3*9^2 - 0.5*(3+14)*1.588^2
=100.065 Joules
B) velocity of A=1.588 m/s
C)velocty of B=1.588 m/s
D)now let the velcotiy of A be x and that of B be y.so, conserving momentum and energy,
3*9 = 3*x + 14*y
conserving energy,
0.5*3*9^2 = 0.5*3*x^2 + 0.5*14*y^2
solving ,we get x= -5.82 m/s
y=3.17 m/s
so velocity of A = -5.82 m/s
E)velocity of B = 3.17 m/s