Freed Point 4. An unknown mass is attached to a light inextensible string which has a length of 3.2 m. The other end of the string is attached to a fixed point. The mass is made to move in a 32m / 30 horizontal circle as shown in the diagram. When the angle between the string and the vertical axis through the fixed point is 30", calculate: R a) the speed of the mass b) the frequency of the mass in revolutions per minute.5. A child has a mass of 5.0 x 10' kg and swings on a rope 4 m long. What is the tension in the rope if the child is travelling at 6 m's as the swings past the lowest point? 6. A bridge over a small river has a roadway which is in the shape of an arch having radius of curvature of 4. x 10' m. What is the maximum speed at which an automobile can travel across the bridge without leaving the bridge? 7. A motorcycle and rider perform the stunt of circling in a cylindrical track with its axis horizontal. The diameter of the track is 1.0 x 10' m. The total mass of the rider and the motorcycle is 2.0 x 10"kg. a) What is the force with which the motorcycle presses against the track at the highest point if the speed is 12 m/'s? b) What is the minimum speed at the highest point if the motorcycle is not to fall from the track?1. A 2 kg stone at the end of a string 0.5 m long is whirled in a horizontal circle. If the magnitude of the maximum tension that the string can withstand is 36 N, calculate the speed of rotation which would break the string. 2. A 45 kg girl swings on a 2.4 m long light swing with two ropes. At the lowest point in her swing, the girl's speed is 5 m/s. Calculate the magnitude of the tension in each rope of the swing when the girl is at the lowest point of her swing. 3. A 0.5 m long rope is used to whirl a 1 kg mass in a vertical circle. When the mass is at the highest point, its speed was 2.5 m's. Calculate the magnitude of the tension in the rope when the mass is at the highest point