Question

Please answer the question below and show full working - How long does it take a 1500-Kg car to stop from a velocity of 45 m/s if a braking force of 4000 N used? If the braking force is increased 3-fold, would the car stop faster? How long would it take?

Answer 1

Time to stop the car = 16.875 seconds

YES

5.625 seconds

Explanation:

Retardation = F / m

= 4000 ÷ 1500

= 2.6666666667 m/ s2

we know v = u + at

so t = ( v - u ) / a

= ( 0 - 45) ÷(- 2.6666666667)

= 16.875 seconds

If the braking force is increased 3-fold, would the car stop faster?

Yes

How long would it take?

5.625 seconds