An electric grinder uses a grinding wheel of 12 cm radius. It takes the electric motor 3.0 s to reach its rated speed of 1500 rev/min starting from rest. Find (a) the angular acceleration, (b) the total angular displacement, and (c) the tangential velocity at the rim of the grinding wheel at the rated speed.

You have been hired to design a spring-launched roller coaster thatwill carry two passengers per car. the car goes up a 10-m highhill, then descends 15m to the track's lowest point. you'vedetermined that the spring can be compressed a maximum o 2.0m andthat a loaded car will have a maximum mass of 400kg. for safetyreasons, the spring constant should be 10% larger than the minimumneeded for the car to just make it over the top. a) what spring constant (k) should you specify ? b) what is the maximum speed of a 350 kg car if the spring iscompressed the full amount.