How fast would a particle be traveling relative to an experimenter in order to have a measured mass that is 20 times its rest mass?

Player kicks a soccer ball from ground level and sends it flying at an angle of 30 degrees at a speed of 26 m/s. what is the horizontal velocity component of the ball to the nearest tenth of a m/s?

If gases like carbon dioxide and methane make up less than 1% of the total atmosphere, why is it important for scientists to monitor changes in percentages of these gases?

Atwo-stage air compressor operates at steady state, compression 10m^3/min of air from 100 kpa and 300k to 1200 kpa. an intercooler between the two stages cools the air to 300k at a constant pressure of 350 kpa. the compression processes are isentropic. a) calculate the power required to run the compressor, in kw b) compare the result to the power required for isentropic compression from the same inlet state to the same final pressure.