# What is the perpendicular component of the rate of change?

A child of mass 22 kg swings at the end of an elastic cord. At the bottom of the swing, the child's velocity is horizontal, and the speed is 6 m/s. At this instant the cord is 3.70 m long.

At this instant, what is the perpendicular component of the rate of change of the child's momentum?

mv^2/r

## The Attempt at a Solution

i tried 22*6^s divded by 3.70
and got 214.05. but its wrong can someone help me please thanks!

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PhanthomJay
Homework Helper
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A child of mass 22 kg swings at the end of an elastic cord. At the bottom of the swing, the child's velocity is horizontal, and the speed is 6 m/s. At this instant the cord is 3.70 m long.

At this instant, what is the perpendicular component of the rate of change of the child's momentum?
you mean the horizontal component is 0, don't you? But regardless of what the horizontal component is, the problem is asking for the perpendicular component of the rate of change of the child's momentum, which is the net force acting on the child in the centripetal direction, for which it appears you have, by chance or intent, the correct equation.

mv^2/r

## The Attempt at a Solution

i tried 22*6^s divded by 3.70
and got 214.05. but its wrong can someone help me please thanks!
Maybe it's a significant figure thing? Try 210, no decimal points please, and don't forget the units associated with this number!