Question

A 2 kg mass starts from rest on an inclined smooth surface with inclination 30^o and length 2 m. How much will it travel before coming to rest on a surface with coefficient of friction 0.25

• A. 4 m
• B. 6 m
• C. 8 m
• D. 2 m

Answer 1

Answer: (A)

4 m

Answer 2

$v^{2} = u^{2} + 2aS = 0 + 2 \times g\sin 30 \times 2$ $v = \sqrt{20}$

Let it travel distance ‘S’ before coming to rest

$S = \frac{v^{2}}{2\mu g} = \frac{20}{2 \times 0.25 \times 10} = 4m.$

$\therefore$ ${\omega\sqrt{\frac{g}{\mu r}}}_{\min}$