A small block is placed on a turntable that is rotating at 45 rpm. The coefficie
ID: 1455556 • Letter: A
Question
A small block is placed on a turntable that is rotating at 45 rpm. The coefficient of static friction between the block and the turntable is 0.2 and when the block is located at a radial position of 7 cm from the center, it does not slip off the rotating turntable. Determine which of the following changes will make the block MORE likely or LESS likely to slip off. In each case, the change indicated is the ONLY change made (for that statement).
True False If the radial position of the block increases, the block is more likely to slip off.
True False If the whole apparatus is moved to the Moon, the block is more likely to slip off.
True False If the angular speed of the turntable increases, the block is more likely to slip off.
True False If the mass of the block increases, the block is less likely to slip off.
True False If the coeff. of friction increases, the block is less likely to slip off.
Please show work
Explanation / Answer
Here ,
angular velocity , w = 45 rpm
w = 45 * 2pi/60 rad/s
w = 4.712 rad/s
coefficient of friction , u = 0.20
position of block , r = 7 cm
r = 0.07 m
as the centripetal acceleration is given as
ac = w^2 * r
now ,
True If the radial position of the block increases, the block is more likely to slip off. as the centripetal acceleration increases.
True If the whole apparatus is moved to the Moon, the block is more likely to slip off. as the frictional force will decrease.
True If the angular speed of the turntable increases, the block is more likely to slip off. as the centripetal acceleration increases.
False If the mass of the block increases, the block is less likely to slip off. as the acceleration is not dependent on the static.
True If the coeff. of friction increases, the block is less likely to slip off. True , as the frictional force will increase