Avertical piston-cylinder assembly containing a gas is placed on a hot plate. the piston initially rests on stops and has a mass of 50 kg, while atmospheric pressure is patm = 101.325 kpa. let the area of the piston be a = 0.01 m2 and assume that gravity is g = 9.81 m/s2 . a) (5 pts) at what pressure, in kpa, will the piston begin to rise? b) (5 pts) assume the piston rises 10 cm. if the amount of work done by the gas equals the change in total energy of the piston, how much work has been done, in j?

Boxing gloves are padded to lessen the force of a blow. (a) calculate the force exerted by a boxing glove on an opponent’s face, if the glove and face compress 7.50 cm during a blow in which the 7.00-kg arm and glove are brought to rest from an initial speed of 10.0 m/s. (b) calculate the force exerted by an identical blow in the gory old days when no gloves were used and the knuckles and face would compress only 2.00 cm. (c) discuss the magnitude of the force with glove on. does it seem high enough to cause damage even though it is lower than the force with no glove?

The speed of light can be used to measure the

An important dimensionless parameter concerned with very high-speed flow is the mach number, defined as v/c, where v is the speed of the object such as an airplane or projectile, and c is the speed of sound in the fluid surrounding the object. for a projectile traveling at 1170 mph through air at 50 ˚f and standard atmospheric pressure, what is the value of the mach number?