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Sat 12 Nov, 2005 11:54 pm
Hi all! I can't do this problem:
A car is on a circular track. It starts accelerating at a certain rate, however friction limits it to some final speed. What angle does the car have to travel until it reaches its top speed?
Can't use any kinematics equations because the acceleration is always changing.
Calculus is involved.
Please advise. Thanks!
you can use kinematic to solve this poblem bacause the frictional force in this case is the centripetal force. It directs towards the centre of the track
Give it a try.
I can't. I'm stuck on this. Please show me how to do this. Thanks!
sorry for the wrong suggestion
i'm not sure about the way frictional force act on the car
however , i have some good ideas which may help you to answer the question
i think in the tangent direction to the track, frictional force increase the car speed. Let's consider the movement of the wheel of the car
when the car move towards, the movement of the wheel is in the clockwise direction. Since frictional force always acts in the opposite dicrection of movement, the firtional force act in the same direction of that of the movement of the car. Therefore, in this case the frictional force helps the car to move towards, or it helps to accelerate the car more.
This also explains why frictional force is important in our lives. Without it , we can't move
If acceleration is given, and the radius is given, just figure out at what speed the centripetal force equals m*acceleration.
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