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shenwei1988

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**[SOLVED] force problems**

A 7.79 kg toy car now starts at rest and is going around a circular track of radius 38.5 m, the accelerates at a constant rate to a final speed of 5.13 m/s in 6 seconds. At the instant it reaches its final speed, find:1.the magnitude of the inward force needed to keep it moving in a circle

2.the magnitude of the tangential force

F=ma

a=v2/r

question1. F=mv2/r=7.79(5.13)(5.13)/38.5=5.32. and that's is right.

question2. the magnitude of the tangential force, i don't know what to do with it ,can anybody help me?