Question

Answer the following problem. Show your solution.

1. A stone which has a mass of 1.27 kg is tied to a rope of 9 m and moved in a circular motion. If it is moving at the rate of 5 m/s.What is the centripetal force acting on it?

2. A 1500kg truck, running at a speed of 10.5 m/s.What is the cemtripetal force acting on it?

3. What is the centripetal force of an 9000-kg train, running at a speed of 27.8 m/s and rounding a curve with a curvature radius of 150 m?

Answer 1

1

$$F=\frac{mv^2}{r}=\frac{1.27\:\rm kg*(5\: m/s)^2}{9\:\rm m}=3.5\:\rm N$$

2. When the trajectory of motion is a straight line, the centripetal force is zero.

3.

$$F=\frac{mv^2}{r}=\frac{9000\:\rm kg*(27.8\: m/s)^2}{150\:\rm m}=46370\:\rm N$$