An amusement ride consists of a car moving in a vertical circle on the end of a rigid boom. The radius of the circle is 10 m. The combined weight of the car and riders is 5.0 kN. At the top of the circle the car has a speed of 5.0 m/s which is not changing at that instant. What is the force of the boom on the car at the top of the circle?
A) 3.7 kN down
B) 1.3 kN down
C) 6.3 kN up
D) 3.7 kN up
E) 5.2 kN down

Question

Quizplus · Accepted Answer

At the top of the circle, the car is moving in a horizontal direction and the weight vector is pointing downwards. Therefore, the only force acting on the car at the top of the circle is the tension force from the boom.

Using the centripetal force formula, we can find the tension force:

F = mv^2/r = (5000 N)/(10 m) = 500 N

This tension force is pointing upwards, so the force of the boom on the car must be equal and opposite, pointing downwards.

Therefore, the answer is D, 3.7 kN up.

An Amusement Ride Consists of a Car Moving in a Vertical