Question

How long will it take a force of 10n to stop a mass of 2.5 kg which is the moving at 20 m per second?

Answer 1

p = mv

Here p = 2.5 * 20 = 50 kg m/s

F= p/t

10= 50/t

t= 5 second

Answer 2

F=ma

10=2.5×a

a=10/2.5=4

as force is retarding a=-4m/s

${v}^{2} - {u}^{2} = 2as$

0^2-20^2=2(-4)s

-400= -4×2s

s=50m