How many horsepower are required to compress 20 lbmol⁄hr of helium = 1.666) from 1 atm at 68°f to 10 atm using (a) a single adiabatic compressor? (b) a two-stage, adiabatic compressor with optimum inter-stage pressure and inter-stage cooling to 68°f? (see textbook for example.)

It's a snowy day and you're pulling a friend along a level road on a sled. you've both been taking physics, so she asks what you think the coefficient of friction between the sled and the snow is. you've been walking at a steady 1.5m/s, and the rope pulls up on the sled at a 32 ∘ angle. you estimate that the mass of the sled, with your friend on it, is 65 kg and that you're pulling with a force of 80 n .