Ball of mass 0.4 kg is attached to the end of a light stringand whirled in a vertical circle of radius R = 2.9 m abouta fixed point. Find the magnitude of the tension when themass is at the top if its speed at the top is 8.5 m/s.(

Explanation:

The net force exerted on the mass is the sum of tension force and the external force of gravity.

is the tension force. is the force of gravity.

where is the rope's radius from the fixed point.

From the net force equation above:

Hence the tension force is 6.046N

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