Question

A force acts for 10s on a stationary body of mass 100kg after which the force ceases to act . the body moves through a distance of 100m in the next 5s . calcluate (i) the velocityacquired by the body,(ii) the acceleration produced by the force ,(iii)the magnitude of the force

Answer 1

say initial velocity is 0
then, v=u+at
v= 0+ a10
v=10a

After 10s body starts moving and cover 100m in 5s

S= vt
100= (10a) 5
a=2m/s2

using the value of a in F=ma
F=100x2=200N
and v=10a =10 x 2= 20m/s

Answer 2

Given that,

Mass of a body, m = 100 kg

A force acts for 10s on it. The body moves through a distance of 100m in the next 5s.

To find,

(i) the velocity acquired by the body,(ii) the acceleration produced by the force (iii)the magnitude of the force

Solution,

Initial velocity of the body, u = 0

(i) Let v is the final velocity. Using first equation of motion as :

v = u +at

v=a(10) ....(1)

After 10 s, body moves through a distance of 100m in the next 5s. SO,

d = vt

100 = 10a × 5

(ii) a = 2 m/s²

Put in equation (1), we get :

v = (2) (10)

v = 20 m/s

(iii) Force produced is given by :

F = ma

F = 100 × 2

F = 200 N

Hence, this is the required solution.