Question

13. A constant retarding force of 50N is applied to an object of mass 20 kg moving initially with a velocity of 15 mis 5 a How long does the object take to stop? b. What distance would it cover during the time?
​

Answer 1

u=15m/s. v=0. As F=ma. a=50/20=2.5m/s^2.

Answer 2

A constant retarding force of 50N is applied to an object of mass 20 kg moving initially with a velocity of 15 mis 5 a How long does the object take to stop? b. What distance would it cover during the time?

Force = 50 N

Mass = 20 kg

Moving initially with a velocity

Time = 15 min

Initial velocity = 15 m/sec

Now , NEWTON'S SECOND LAW

F = M×a

50 = 20×a

a = 2.5 m/s²

Since ,

v = u+at

final velocity is 0

t = 15/2.5

= 6/2 sec

Now , S = ut+1/2 at²

so , 90-45

So body will stop for 6 second and travel 45 m in that time .