Question

A car whose total mass is 800kg travelling with a uniform velocity of 20m/s suddenly observes a stationary dog on it's path 50m ahead. If the total force applied on the breaking system on the car by the driver is 2000N what would most probably happen

Answer 1

Driver hits the dog

Step-by-step explanation:

From kinematics equation

`v_f^(2)=v_i^(2)+2as` and making a the subject

`a=\frac {v_f^(2)-v_i^(2)}{2s}=\frac {0-20^(2)}{2*50}=-4m/s^(2)`

F=ma=800*-4=-3200 N

The driver is required to apply a force of 3200 N to effectively not hit the dog. However, when the driver applies 2000 N, this is less the required force by 1200 N hence the driver hits the dog.