Vertical Cable Management

1) You work in a research group involving more bus Cited energy efficient. One option is to store energy in a rotating wheel at the bus stop and then use it to speed up the bus. The steering wheel is a small consideration, but the disc extremely strong composite carbon fiber rim with a heavy iron mass of 51.7 kg. The proposed radius of the disk is 1.49 m.

Your boss is concerned that the ring may end up turning so fast that the bearings overheating. To see if it is likely you have been invited to determine how quickly (in radians per second), the wheel would be if it started from rest, and has absorbed all the energy of motion of a bus 29707.53 kg mass when it decelerates to a speed of 13.31 m / s down to a halt. The answer must have at least one decimal place.

2) The automatic feathering system sensitization on a horizontal pole attached to the vertical wall outside a tall building is jammed. The management of the building wants to send a person to crawl along the mast to fix the problem. You have been invited to consult a group to decide whether or not this is possible. You are all too well that nobody could survive the fall of 80 m mast on the ground. The mast is a steel I-beam 61.63 kg which is very strong and rigid. One side of the flagpole is attached to the building wall by a hinge so that it can rotate vertically. 11.2 m away, the other end of the flagpole is attached to a strong, lightweight cable. The cable passes from the pole at an angle of 29.10 ° to the horizontal until it reaches the building where it is bolted to the wall. The mechanic will be mounted on the mast weighs 75.97 kg including the hardware. Your boss has asked you to calculate the tension in the cable when the mechanic is at the end of the mast. The answer must have at least one decimal place in Newton. g = 9.8 [m / s ^ 2]

Sorry to have read a long text like this ...

I would say to the boss to buy better bearings. Case closed.