Question

A capstan is a rotating drum or cylinder over which a rope or cord slides in order to provide a great amplification of the rope's tension while keeping both ends free . Since the added tension in the rope is due to friction, the capstan generates thermal energy.

A capstan is a rotating drum or cylinder over which a rope or cord slides in order to provide a great amplification of the rope's tension while keeping both ends free . Since the added tension in the rope is due to friction, the capstan generates thermal energy.A) If the difference in tension between the two ends of the rope is 520 N and the capstan has a diameter of 10.0 cm and turns once in 0.900 s, find the rate at which thermal energy is generated.B) If the capstan is made of iron and has mass 6.00 kg, at what rate does its temperature rise? Assume that the temperature in the capstan is uniform and that all the thermal energy generated flows into it. (unit C/s)

A) If the difference in tension between the two ends of the rope is 520 and the capstan has a diameter of 10.0 and turns once in 0.900 , find the rate at which thermal energy is generated.

B) If the capstan is made of iron and has mass 6.00 , at what rate does its temperature rise? Assume that the temperature in the capstan is uniform and that all the thermal energy generated flows into it. (unit C/s)

Answer 1

A) work done per turn = F*d = F*(2πR)

from conservation of energy, thermal energy is generated at rate

F(2πR)/t = (520*3.14*0.10)/0.90 = 181.51 J/s

B) iron has specific heat S = 0.45 J/gC

in one second

181.51 = 0.45 * 6000 *ΔT

ΔT = 0.067 C

temperature rises at rate of 0.067 C/s