Which has more KE, a large truck moving at 50m/s or a bicycle moving at 10m/s?
2 answers:
You might be interested in
Answer:
a)6.67 m/s2
b)16.7 rad/s2
c)increasing angular acceleration
Explanation:
a) It's because the system is not just mass of the man, it consists of the man holding a rope wrapped around a cylinder, not just a man free falling. So you would have to consider the rotating cylinder under the torque created by the man gravity force.
Let g = 10m/s2
T = mgd =75*10*0.4 = 300 N.m
The from the mass moments inertial of the solid cylinder:
we can calculate the angular acceleration of the cylinder:
then translate that to acceleration:
c) if the mass of the rope is not neglected, that means the force of gravity increases as the rope unwrapping around the cylinder, so the torque increases. Also the moment of inertial of the rope-cylinder system decreases due to rope unwrapping. In the end, the angular acceleration is no longer constant, but increasing.