Question

The impulse given to a ball with mass of 4 kg is 28 N s. If the ball were already moving at 3 m/s what would the final velocity be? (Remember that v = Vfinal - Vinitial )

Answer 1

vf = 10 m/s. A ball with mass of 4kg and a impulse given of 28N.s with a  intial velocity of 3m/s would have a final velocity of 10 m/s.

The key to solve this problem is using the equation I = F.Δt = m.Δv, Δv = vf - vi.

The impulse given to the ball with mass 4Kg is 28 N.s. If the ball were already moving at 3 m/s, to calculate its final velocity:

I = m(vf - vi) -------> I = m.vf - m.vi ------> vf = (I + m.vi)/m ------> vf = I/m + vi

Where I 28 N.s, m = 4 Kg, and vi = 3 m/s

vf = (28N.s/4kg) + 3m/s = 7m/s + 3m/s

vf = 10 m/s.

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