How much force does a person have if they’re 90kg

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.

What happens when a rubber rod is rubbed with a piece of fur?

Which radioisotope is used in dating geological formations?