An amusement park ride consists of a car moving in a vertical circle on the end of a rigid boom of negligible mass. The combined weight of the car and riders is 4.9 kN, and the radius of the circle is 12 m. At the top of the circle, (a) what is the force FB on the car from the boom (using the minus sign for downward direction) if the car's speed is v = 5.0 m/s? (b) What is FB if v = 13 m/s?

I got 5940N and 11934N respectively but both are apparently wrong..

Question

An amusement park ride consists of a car moving in a vertical circle on the end of a rigid boom of negligible mass. The combined weight of the car and riders is 4.9 kN, and the radius of the circle is 12 m. At the top of the circle, (a) what is the force FB on the car from the boom (using the minus sign for downward direction) if the car's speed is v = 5.0 m/s? (b) What is FB if v = 13 m/s?

I got 5940N and 11934N respectively but both are apparently wrong..