Atrain car with mass m1 = 515 kg is moving to the right with a speed of v1 = 7.5 m/s and collides with a second train car. the two cars latch together during the collision and then move off to the right at vf = 4.8 m/s. now the same two cars are involved in a second collision. the first car is again moving to the right with a speed of v1 = 7.5 m/s and collides with the second train car that is now moving to the left with a velocity v2 = -6 m/s before the collision. the two cars latch together at impact. what is the final velocity of the two-car system? (a positive velocity means the two train cars move to the right – a negative velocity means the two train cars move to the left.)

Which type of electromagnetic waves are dangerous enough to be used to kill cancerous cells? (a)gamma rays (b)visible light (c)infrared light (d)microwaves

Steam is generated in a boiler of a cogeneration plant at 10 mpa and 450°c at a steady rate of 5 kg/s. in normal operation, steam expands in a turbine to a pressure of 0.5 mpa and is then routed to the process heater, where it supplies the process heat. steam leaves the process heater as a saturated liquid and is pumped to the boiler pressure. in this mode, no steam passes through a condenser, which operates at 20 kpa. (a) determine the power produced in the turbine and the rate at which process heat is supplied in this mode. (b) determine the power produced in the turbine and the rate of process heat supplied if only 60 percent of the steam is routed to the process heater and the remainder is expanded to the condenser pressure. (3.32 mw; 9.69 mw; 4.25 mw; 5.82 mw)

Could someone me find the answer to this problem.