Young David who slew Goliath experimented with slings before tackling the giant. He found that he could re- volve a sling of length 0.600 m at the rate of 8.00 rev/s. If he increased the length to 0.900 m, he could revolve the sling only 6.00 times per second. (a) Which rate of rotation gives the greater speed for the stone at the end of the sling? (b) What is the centripetal acceleration of the stone at 8.00 rev/s? (c) What is the centripetal ac- celeration at 6.00 rev/s?

You have a horizontal grindstone (a disk) that is 87 kg, has a 0.31 m radius, is turning at 94 rpm (in the positive direction), and you press a steel axe against the edge with a force of 23 N in the radial direction. The kinetic coefficient of friction between steel and stone is 0.20. What is the number of turns, N, that the stone will make before coming to rest?

Now we have a rod-shaped space station of length 1296 m and mass 1.43 x 10^6 kg, which can change its length (kind of like an old-fashioned telescope), without changing its overall mass. Suppose that the station is initially rotating at a constant rate of 1.83 rpm. If the length of the rod is reduced to 1.83 m, what will be the new rotation rate of the space station? 1. 3.01 rpm 6.27 rpm 3 3.76 rpm 4 9.41 rpm

A washing machine needs 17.1 s to speed up from rest to top speed of 5 rotation for every 3.05 s. If the damp cloths inside are 9.87 cm from the center, what is it's radial acceleration at top speed?