A5.0 g coin is placed 15 cm from the center of a turntable. the coin has static and kinetic coefficients of friction with the turntable surface of μs = 0.70 and μk= 0.50. the turntable very slowly speeds up.

what is the angular speed in rpm when the coin slides off?

Explanation:

The coin will slide when the centripetal force is too much for the friction to hold, that is, when it is equal to the maximum static friction, so:

Or:

Which means (since on the vertical direction only the normal and weight are acting):

So for our values we have:

Since , we convert our angular speed using this conversion factor (which is equal to 1 thus not altering our result):

see the picture for the vector

the magnitude of the vector by pythagorean theorem

r = √( (-10)^2 + (3)^2 ) = √109

magnitude = √109 units

the direction angle between vector and x-axis is

tan^(-1)(3/10) = 16.699

so the direction is approximately 16.7 degrees north of west

answer: 2×10^-2kg

explanation: density= mass per volume

vol=mass/density

converting to s.i units we have;

3÷1000kg = 0.003

1.5÷100m = 0.15

0.003/0.15 = 0.02kg