A 57g tennis ball is served at 45 m/s?

A 57g tennis ball is served at 45 m/s?

If the ball started from rest, what impulse was applied to the ball by the racket?

Answer:

Impulse is in Ns (newton-seconds).

FΔt = mΔv

Impules = mΔv = 0.057kg (vf-vi) = 0.057kg (45m/s-0.0m/s) = (0.057kg (45m/s) = 2.565 kgm/s.

Just so you know, 1N = 1kgm/s^2

So, FΔt = (kgm/s^2)(s)=kgm/s

Impulse is product of force and time (I = F x t).

Now,we know that

F=ma

since a=v/t so

F=mv/t

now take “t” to the left side

F x t = mv

or simply

Impulse = mv = 0.057kg x 45m/s = 2.565Ns (answer)

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