Question

a ball of mass 100 g moving with a velocity of 30 m/s collide with a box of mass 2 kg at rest after collision the box moves with the velocity of 5 m/s. calculate velocity of ball after collision

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Answer 1

Given:-

Mass of the ball(m1)= 100g

=>100/1000

=>1/10kg

Initial velocity of the ball(u1)=30m/s

Mass of the box(m2)=2kg

Initial velocity of the box(u2)=0 (as it was at rest)

Final velocity of the box(v2)=5m/s

To find:-

Final velocity of the ball(v1)

Solution:-

According to conservation of momentum,we get----

=>m1u1+m2u2=m1v1+m2v2

=> 1/10×30+2×0=1/10×v1+2×5

=>3=v1/10+10

=>3-10=v1/10

=>-7=v1/10

=>v1=(-7)10

=>v1= -70m/s

Thus,velocity of the ball after collision is -70m/s or 70m/s in the opposite direction.