Aspinning disc rotating at 130 rev/min slows and stops 31 s later. how many revolutions did the disc make during this time?

Look at the potential energy diagram for a chemical reaction. which statement correctly describes the energy changes that occur in the forward reaction?

An ideal otto cycle has a compression ratio of 10.5, takes in air at 90 kpa and 40°c, and is repeated 2500 times per minute. using constant specific heats at room temperature, determine the thermal efficiency of this cycle and the rate of heat input if the cycle is to produce 90 kw of power.

Four friends, a, b, c, and d are standing varying distances away from a speaker which is producing sound waves.