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 )

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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it's when something is going so fast it makes a loud noise, breaking the sound barrier, for example: a jet makes a loud noise, not only cause of the jet but because they reached a point where they went so fast that you can year the noise from various parts, kinda like a police car, lets say the car was going   so fast that you hear the siren of the cop car right next to you, but the car is probably a mile a way, it's cos the siren was next to you a few seconds if you understand me