Question

A block of mass 0.5 kg is kept on a rough inclined plane making an angle of ${30}^o$ with horizontal.What power will be required to move the block up the plane(among the plane) with a velocity of 5m/s?(Take $\mu$=0.2 between block and plane)

• A. 16.825 N-m/s
• B. 16.822 N-m/s
• C. 16.852 N-m/s
• D. 16.828 N-m/s

Answer 1

Answer: (A)

16.825 N-m/s

REF.Image

$F=f+mgsin{30}^{\circ }$

$=\mu mgcos30+mgsin{30}^{\circ }$

$f=[0.2\times \frac{\sqrt{3}}{2}+\frac{1}{2}]mg$

$f=\frac{(0.2\times \sqrt{3}+1)}{2}\times 0.5\times 10$

f is $(0.173+0.5)5$

f is $0.673\times 5N$

power will be = fv

$=0.673\times 5\times 5$

$=16.325N-m/s$

Hence (a) option is correct answer.