Physics: Elastic Collision or Energy Theorem AK W Impulse-Momentum Theorem: A ca
ID: 2001757 • Letter: P
Question
Physics:
Elastic Collision or Energy Theorem AK W Impulse-Momentum Theorem: A cart is traveling at 3.0 m/s along a horizontal, frictionless track into a wall. The cart rebounds off of a spring attached to the wall with a speed of 3.0 m/s in the opposite direction. Which of the following is true of the force by the spring on the cart during this motion? I. The impulse is zero but the work is non-zero. II. The work is zero and the impulse is non-zero. III. Both the work and the impulse are zero IV. Both the work and the impulse are non-zero.Explanation / Answer
1 .) II .workdone is zero and impulse is non zero
as we know, workdone = change in kinetic energy and here change is kinetic energy is zero so work done willl be zero
impule is change in momentum and here there is change in momentum as direction of velocity gets change hence impluse would be non zero.
2.)
I. it will gain maximum speed at the equilibrium position i.e at point xe
II.)friction force(F) = coefficient of Kinetic friction * N { N = mg }
work done by sprng = change in kinetic energy of object + work done by frictional force
0.5 k x^2 = 0.5 m v^2 + F.x
v = sqrt (0.5 * 80 * 0.5^2 - 0.4 * 2* 9.81 ) / (0.5 *2)
v = 1.466 m/s
maximum speed of m/s
III.) kinetic energy of object will convert into wor k done by frictional force when the velocity of object become zero
0.5*m*v^2 = F.d
d= 0.5 *2 * 1.466^2/(0.4*2*9.81) = 0.1867 m
at 0.1867 +0.5 = 0.6867 m from the compression of spring.