Question

Force of 10 N is acting on a body of mass 1 kg. If it covers a distance of 0.001 km in 4 seconds moving along a straight line, find its initial velocity.

Answer 1

Hi,

Here is your answer

Given:

Force(F)=10N

Mass(m)=1kg

Distance(s)=0.001km=1m

Time taken(t)=4s

To find:

Initial velocity(u)

Solution:

We know that

Force=Mass×Acceleration

Hence

Acceleration=Force/Mass

Substituting the given datas

We get,

Acceleration=10/1=10m/s²

By second equation of motion

s=ut+1/2×a×t²

Substituting the datas

We get,

1=u×4+1/2×10×4²

u= -19.75m/s

The negative direction indicates that the direction of initial velocity is in the direction opposite to that of force applied.

Notes:

The three equations of motion are

• v=u+at
• s=ut+1/2×a×t²
• v²-u=2as

Hope this helps you.