A coin is projected with speed 6ms-1 along a horizontal surface of a bench. The coefficient of friction between the coin and the surface is 0.7. Modelling the coin as a particle, and assuming no air resistance, find the speed of the coin after 0.3s.
t = 0.3
mu = 0.7
u = 6ms-1
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Where do I start with this friction question? watch
- Thread Starter
- 01-02-2010 21:47
- 01-02-2010 22:23
The only force acting on the coin is friction...
Friction = 0.7 x R
We don't know the mass of the coin, but as the bench is horizontal, R=mg
Friction = 0.7 x mg
0.7 x mg = ma
Can you see where to go from here?
The key is realising that the answer is not dependent on the mass of the coin