Question

A man cycles up a hill rising 1 metre vertically for every 20 meters along the slope at a rate of 7.2km/hr. If the weight of the man and cycles is 100 kg, the power of the man [$g=10m/s^2$]

• A. 6 watt
• B. 12 watt
• C. 24 watt
• D. 98 watt

Answer 1

The correct option is D 98 watt

Given,

Velocity, $v=7.2km/h=7.5\times \frac{7}{18}=2m/s$

Slope, $sin\theta =\frac{1}{20}$

Mass, $m=100$

When man and cycle moves up then, component of weight opposes it's motion, That is,

$F=mgsin\theta$

So,

Power of man $P=F\times v=mgsin\theta \times v$

$=100\times 9.8\times \frac{1}{20}\times 2=98watt$