Question

A body of mass 2kg having a velocity of 2m/s is brought to rest within a distance of 2m . Find the force acting on it

Answer 1

v^2 = 2as
a= v^2/ 2s= 4/ 4= 1 m/sec^2
F = ma= 2 N

Answer 2

Given,

mass of body = 2kg

intial velocity (u)= 2m/s

final velocity (v)= 0 m/s

Distance covered before coming to rest (s) = 2m

To find,

The retarding force acting on this body

Solution :

Using third law of motion ,

v^2 = u^2 + 2as

Plugging the values that we know .

0 = (2)^2 +2×2×a

0 = 4+4a

4a = -4

a = -1 m/sec^2

Retarding force = mass × acceleration

Putting the values :

Force of retardation = 2×(-1)

= -2m/sec^2 ( Answer )

Answer 3

Given,

mass of body = 2kg

intial velocity (u)= 2m/s

final velocity (v)= 0 m/s

Distance covered before coming to rest (s) = 2m

To find,

The retarding force acting on this body

Solution :

Using third law of motion ,

v^2 = u^2 + 2as

Plugging the values that we know .

0 = (2)^2 +2×2×a

0 = 4+4a

4a = -4

a = -1 m/sec^2

Retarding force = mass × acceleration

Putting the values :

Force of retardation = 2×(-1)

= -2m/sec^2 ( Answer )