Question

A 1000.kg car moving at north at 100. km/hr brakes to a stop in 50. m within a uniform acceleration. what are magnitude and direction of the net force on the car ?
thank you so much

Answer 1

Answer:

Force=7.71KN in the opposite direction

Explanation:

Given the mass of the car(M)=1000Kg

The initial speed of the car(u)=100km/hr

we know that 1km/hr=5/18 m/sec

100km/hr=100*5/18 m/sec=27.77m/sec

the distance travelled before it stops (s)=50m

let the acceleration of the car be a

The final velocity of the car is 0.

we know that  $v^{2}-u^{2}=2as$

$0^{2}-27.77^{2}=2(-a)(50)$

a=7.712m/$sec^{2}$

We know that F=Ma

F=1000* 7.712=7712N=7.71KN