Question

To slow down a car, a braking force of 1200 newtons is
applied for 10 seconds. How much force would be needed
to produce the same change in velocity in 6 seconds
(a) 2000 N
(b) 3000 N
(c) 2500 N
(d) 1500 N​

Answer 1

Explanation:

(a) 2000N change in momentum will be same as velocity

Answer 2

(a) 2000N

F = 1200N

t = 10s

F = ma

= m ∆v / ∆t

1200 = m∆v / 10

m∆v = 12000

Now ,

∆t = 6 s

F' = m∆v / ∆t

F' = 12000 / 6

= 2000N