Question

Which person would experience the greatest force of impact in a sudden collision? A 200 lb. man traveling 20 mph b 150 lb. woman at 30 mph d 35 lb. infant at 75 mph e 75 lb. child at 55 mph

Answer 1

Answer:

The 150 lb woman at 30 mph would experience the greatest force of impact in a sudden collision.

Explanation:

Momentum

The force of impact exerted on an moving object that suddenly stops or changes its movement is measures by the physics magnitude called Impulse, which can be computed with the formula

$I=F.t$

Where F is the force and t is the time that force acts to produce the impact on the object. The impulse is also defined as the change in the momentum of the object:

$I=\Delta p=p_2-p_1$

Or equivalently

$I=m(v_2-v_1)$

The question describes four situations where different persons and object suffer impact that make them stop from their moving state. Thus $v_2=0$ and the impulse is

$I=-m.v_1$

We are only interested in the relative magnitudes of each case, so we won't consider the sign in the calculations

Case 1: A 200 lb. man traveling 20 mph  

$I_1=200(20)=4000\ lb.mph$

Case 2: A 150 lb. woman at 30 mph

$I_2=150(30)=4500\ lb.mph$

Case 3: A 35 lb. infant at 75 mph

$I_3=35(75)=2625\ lb.mph$

Case 4: A 75 lb. child at 55 mph

$I_4=75(55)=4125\ lb.mph$

By comparing the results, we can see that the 150 lb woman at 30 mph would experience the greatest force of impact in a sudden collision.