Answer:
a) 720N
Step-by-step explanation:
Centrifugal force pushing student upwards at the top Fc = (643 - 566)N = 77N
At the bottom, an equal centrifugal force Fb acts downwards on the student giving a total of :
Fc + 643 = 77 + 643 = 720N
b) The centrifugal force is quadrupled when speed is doubled ,therefore, the total force at the top = 643 - (4× 77)
= (643 - 308)N = 335N
c ) The total force at the top when the centrifugal force is quadrupled = 643 + (4×77)
= (643 + 308 )N = 951 N