Answer:
Explanation:
During a car collision momentum of vehicle ceases within a fraction of seconds so Force due to the impulse is huge.
Impulse is defined as the product of average force and time. If we can increase the period of collision for the same impulse then the average force imparted will be less.
If we can increase the time period then damage due to collision will be less.
Answer:0.318 revolutions
Explanation:
Given
Initially Propeller is at rest i.e. 
after 

using 


Revolutions turned in 2 s



To get revolution 
=
Answer:
0.074m/s
Explanation:
We need the formula for conservation of momentum in a collision, this equation is given by,

Where,
= mass of ball
= mass of the person
= Velocity of ball before collision
= Velocity of the person before collision
= velocity of ball afer collision
= velocity of the person after collision
We know that after the collision, as the person as the ball have both the same velocity, then,


Re-arrenge to find
,

Our values are,
= 0.425kg
= 12m/s
= 68.5kg
= 0m/s
Substituting,


<em />
<em>The speed of the person would be 0.074m/s after the collision between him/her and the ball</em>