Question

a coin is kept at distance 10cm at distance for a center of a turn table of radius 1m just being to slep when turn table rotate at speed of 90rpm calculate the coifient of static fraction between coin and turn table​

Answer 1

Answer:

9(π)^2/100 or 0.9

Explanation:

Angular speed =Angular displacement/Time

Radius of table=1m

Time for 90 rotations =1 minute=60 seconds.

Time for 90×2πr angular displacement=60 seconds

Therefore Angular speed of Table=90×2π1/60

Angular speed=3π rad/sec

Now, Coin just started to slip.

Force of centripetal = Static friction

Let mass of coin is m

m×(Angular speed)^2×radius where coin is located=u×m×g

where u is static friction coefficient.

m×(3π)^2×10cm=u×m×10m/s^2

9(π)^2×10/100=u×10

u=9(π)^2/100

We can assume π^2=10

So u=0.9(apprx.)