Question

A block starts moving up a fixed inclined plane of inclination 60° with a velocity of 20 m/s and stops after 2 sec. The approximate value of coefficient of friction is (g = 10 m/s²)

• A. 3
• B. 3.3
• C. 0.27
• D. 0.33

Answer 1

Answer: (C)

0.27

Answer 2

Retardation = g (sin q + m cos q) = 5$(\sqrt{3} + \mu)$

Now v = u – at

\ a = $\frac{u}{t}$ as v = 0

\ $5(\sqrt{3} + \mu)$ = 10 Ž m = 0.27