Question

A block of mass 1 kg slides down on a rough inclined plane of inclination 60^o starting from its top. If the coefficient of kinetic friction is 0.5 and length of the plane is 1 m, then work done against friction is(Take g = 9.8 m/s²)

• A. 9.82 J
• B. 4.94 J
• C. 2.45J
• D. 1.96 J

Answer 1

Answer: (C)

2.45J

Answer 2

$W = \mu mg\cos\theta.S = 0.5 \times 1 \times 9.8 \times \frac{1}{2}$= 2.45 J.