A car of mass 1000 kg is heading east at 25 m/s. It collides with a car of mass 1200 kg heading north at 30 m/s. When the cars collide, they stick together. a. What is the total momentum of the system before the collision? Remember that momentum is a vector quantity, and write the momentum in component notation, with x and y unit vectors. (1 point)

b. What is the total momentum of the system after the collision? Write the momentum in component notation, with x and y unit vectors. (1 point)

c. What is the velocity of the cars after the collision? Write the velocity in component notation, with x and y unit vectors. (1 point)

d. At what angle do the cars move after the collision? (1 point)

As part of an industrial process, air as an ideal gas at 10 bar, 400k expands at steady state through a valve to a pressure of 4 bar. the mass flow rate of air is 0.5 kg/s. the air then passes through a heat exchanger where it is cooled to a temperature of 295k with negligible change in pressure. the valve can be modeled as a throttling process, and kinetic and potential energy effects can be neglected. (a) for a control volume enclosing the valve and heat exchanger and enough of the local surroundings that the heat transfer occurs at the ambient temperature of 295 k, determine the rate of entropy production, in kw/k. (b) if the expansion valve were replaced by an adiabatic turbine operating isentropically, what would be the entropy production? compare the results of parts (a) and (b) and discuss.

Five structural isomers have the formula c6h14. where needed, draw the structure and give the iupac name of all five isomers.

Aspring has a relaxed length of 33 cm (0.33 m) and its spring stiffness is 6 n/m. you glue a 76 gram block (0.076 kg) to the top of the spring, and push the block down, compressing the spring so its total length is 15 cm. you make sure the block is at rest, then at time t=0 you quickly move your hand away. the block begins to move upward, because the upward force on the block by the spring is greater than the downward force on the block by the earth. calculate y vs. time for the block during a 0.09-second interval after you release the block, by applying the momentum principle in three steps each of 0.03-second duration.