Question

A body is moving with uniform velocity of 2 m s­1

on a

rough level surface. The frictional force on it is 10 N. If

the body moves with velocity 4 m s­1 the force of

friction will be:

(a) 2.5 N (b) 5 N

(c) 10 N (d) 20 N

Answer 1

is this your answer?

Answer 2

Hey dear,

◆ Answer-
F2 = 20 N

◆ Explanation-
# Given-
v1 = 2 m/s
v2 = 4 m/s
F1 = 10 N

# Solution-
As we know, frictional force depends on the velocity of the moving object.
i.e. F ∝ v

Thus, here-
F1/v1 = F2/v2
F2 = F1 × v2 / v1
F2 = 10 × 4 / 2
F2 = 20 N

Therefore, frictional force is 20 N.

Hope it helps...