(4 pts) A bicycle pump has a barrel 65 cm long. On the upstroke, air is drawn into the pump at a pressure of 1 atm. On the downstroke, the air in the barrel is compressed. How long must the downstroke be to increase the pressure of the air in the barrel to 4 atm

A500g object falls off a cliff and losers 100 j from its gravitational potential energy store. if the gravitational field strength g=9.8n/kg, how high is the cliff?

Air is to be preheated by hot exhaust gases in a cross-flow heat exchanger before it enters the furnace. air enters the heat exchanger at 95 kpa and 20°c at a rate of 0.6 m^3/s. the combustion gases (cp = 1.10 kj/kg°c) enter at 160°c at a rate of 0.95 kg/s and leave at 95°c. determine the rate of heat transfer to the air and its outlet temperature.

In the circuit, the switch s has been open for a long time and r = 125 kohm. it is then suddenly closed. (a) determine the time constant before the switch is closed. s (b) determine the time constant after the switch is closed. _ s (c) let the switch be closed at t = 0. find the current in the switch as a function of time. (use t for time. express your answer in milliamps and seconds.) i(t) =_