A tennis ball has a mass of 57 g. A tennis player hits the tennis ball with a tennis racket. The tennis ball has a velocity of 25 m / s when it hits the racket. The velocity of the tennis ball when it leaves the player’s racket is 15 m / s in the opposite direction from its approaching direction. The average force exerted by the tennis racket on the ball is 35 N. For how long is the tennis ball in contact with the tennis racket?​

Answer :

Answer:

0.065 seconds

Explanation:

i) Change in momentum is equal to impulse so, m(v-u) = ft  (Where f is force and t is time)

ii) Since we know the mass of the ball, we change grams to the SI unit of kilograms, kg so 0.057kg

iii) We are also told that the ball CHANGES direction, so we know that the new velocity is the negative value of the initial one,

iv) Putting this all together we get 0.057(25--15) which is the same as 0.057(25 + 15)

v) We get an impulse of 2.28 Ns

vi) We take this value and divide it by 35 as we want the Force alone and not the time,

vii) To which we get 0.065 seconds,

Hope this was helpful!!