Question

A body projected along a rough horizontal surface with 6 ms^-1 cames to rest after travelling a distance of 9 m. Then coefficient of sliding friction is (g = 10ms^-2).

(1) 0.2 

(2) 0.4 

(3) 0.6 

(4) 0.8

Answer 1

Correct option is (1) 0.2 

Given, 

u = 6 m/s, s = 9 m, v = 0

From equation of motion

v² = u² - 2as

0 = (6)² - 2 x a x 9

18 a = 36

⇒ a = 2 m/s²

Coefficient of sliding friction is given by

μ = a/g

\(= \frac {2}{10} = 0.2\)