Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

A 10 kg object moving forward with a speed of 3 m/s collides with a stationary 5

ID: 1634796 • Letter: A

Question

A 10 kg object moving forward with a speed of 3 m/s collides with a stationary 5 kg object and sticks to it. What is the combined speed of two objects after the collision? (A) 1 m/s (B) 2 m/s (C) 3 m/s (D) 4 m/s (E) 5 m/s A ball with a mass of 2 kg hits a wall with a speed of 5 m/s and rebounds with same speed in the opposite direction. What is the magnitude of the impulse that the wall imparted on the ball? (A) 0 N middot s (B) 2 N middot s (C) 5 N middot s (D) 10 N middot s (E) 20 N middot s An object is attached to a spring and oscillates with amplitude A and period T, as represented on the graph shown. The nature of the velocity v and acceleration a of the object at time T/2 is best represented by which of the following? (A) v > 0, a = 0 (B) v 0, a

Explanation / Answer

given

m1=10kg

u1(initial speed)=3m/s

m2=5kg

u2(initial speed of 5kg )=0

they collide and travel with common velocityV

from law of conservation of momentum

V=m1u1/(m1+m2)

=(10x3)/(5+10)

=30/15=2m/s

therefore the common velocity of the two bodies is 2m/s

18)from the given graph at t=T/2 the particle will be mean position and it will have maximum velocity and minimum acceleration(0m/s2)

so option 1 IS CORRECT