Question

A body of mass 2 kg is moving over a
perfectly smooth surface with a
uniform velocity of 5 metre per
second. The external force acting on
the body is
a 10N
b 10dyne
c Zero
d Cannot say

Answer 1

Explanation:

Correct option is

C

Zero

Given

mass =2kg

velocity =10m/s

Then

acceleration =0m/s

2

(because initial velocity = final velocity)

Now as

Force=Mass×Acceleration

=>F=2×0

or Force =0 Newton

Hence,

option c is correct answer.

it is usually

Answer 2

Given

mass =2kg

velocity =5m/s

Then  

as we know that when the body moves with an uniform velocity then acceleration is 0 m/s² since acceleration is 0

acceleration =0m/s2 (because initial velocity = final velocity)

Now as  

Force=Mass × Acceleration

=>F=2×0

or Force =0 Newton

Hence,

Option C, zero is correct answer.