Consider two blocks on a horizontal frictionless surface. Block A has a mass of
ID: 1346959 • Letter: C
Question
Consider two blocks on a horizontal frictionless surface. Block A has a mass of 70.0 kg and block B has a mass of 45.0 kg . Block A is at rest but block B is moving in a straight line at 14.0 m/s toward Block A and eventually collides with block A. After the impact, Block B is found to be traveling with a velocity of 6.00 m/s at an angle of 52.1 degrees with respect to its initial direction of motion. Consider air resistance to be negligible.
A) What is the magnitude of the velocity of Block A, 1.73 seconds after the collision?
Explanation / Answer
m1v1 + m2v2 = m1v1f + m2v2f
70 * 0 + 45 * 14 = 70 * v1f + 45 * [cos 52.1 , sin 52.1]
630 = 70v1f + [27.64 , 35.51 ]
70 v1f = [602.36 , - 35.51]
v1f = [8.605 , -0.507 ]
v1f = 8.62 m/s
part a )
v1f x component will remain same
v1y = vf = vo + gt
vf = -0.507 + 9.8 * 1.73
vfy = 16.447
v1 = sqrt ( 8.605^2 + 16.447^2)
v1 = 18.56 m/s