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Horizontal Circles

Part of the Mechanics section of Coddy's Physics journey. Lesson 74 of 94.

A net force toward the centre keeps an object on its circle:

F_net = m v² / r

It is not a new force: a tension, a friction or a normal force does the job.

A puck on a string: T = mv²/r.

Seen from above: a puck on a frictionless table, tied by a string to a peg at the centre of its circular path; the tension T pulls the puck along the string toward the peg while its velocity v points along the circle

Seen from above: the string tension is the force toward the centre.

A car on a flat curve: fs = mv²/r, up to the friction limit.

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Challenge

A 0.2 kg puck slides in a circle on frictionless ice, tied to a 0.5 m string. The string breaks at a tension of 10 N. Find the fastest speed v the puck can go.

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This lesson includes a short quiz. Start the lesson to answer it and track your progress.

All lessons in Mechanics