A 40 kg child sits on the edge of a carnival ride at a radiu

A 40 kg child sits on the edge of a carnival ride at a radius of 4m. He ride makes 3 revolutions in 6s.

A) The speed of the child is most nearly

a. 4m/s
b. 12m/s
c. 24m/s
d. 120m/s
e. 2880 m/s

B) The force which is holding the child on the ride is most nearly

a. 30 N
b.160 N
c. 320 N
d. 1440 N
e. 2880 N

Solution

A)

T = 6/3 = 2 sec

speed = 2pir/T = 2*3.14*4)/(2) = 12.58 m/s

option B

B)

Net Force = mV^2/R = 40*12.56^2)/(4 = 1577.53 N

option d