Question

A 0.5kg football thrown by Tony Romo with a velocity of 15 m/s is caught by a stationary receiver and brought to rest in 0.02 seconds. a) what impulse is delivered to the ball? b) how much force must be exerted in order to stop the ball?


The answers are -7.5kg m/s and F = -375N, but I don't know how they got them. Steps please! Thank you!!

Answer 1

Answer:

a.-7.5 kg m/s

b.-375 N

Explanation:

We are given that

Mass of football, m=0.5 kg

Initial velocity ,u=15m/s

Final speed ,v=0

Time, t=0.02 s

a. We have to find the impulse delivered to the ball.

We know that

Impulse=Change in momentum

I=m(v-u)

Using the formula

$I=0.5(0-15)=-7.5 kg m/s$

Hence,  the impulse delivered to the ball=-7.5 kg m/s

(b)

We know that

Force,$F=\frac{|mpulse}{time}$

Using the formula

$F=\frac{-7.5}{0.02}=-375 N$