A lab cart with a mass of 15 kg is moving with constant velocity, v, along a straight horizontal track. A student drops a 2 kg mass into it from directly above, and the cart continues moving. Which equation best represents the horizontal momentum in this situation? 15vi 2vi = 15vf 2vf 15vi 2(0) = 15vf 2vf 15vi 2(0) = (15 2)vf 15vi 2vi = (15 2)vf.

The harmonic motion of a particle is given by f(t) = 2 cos(3t) + 3 sin(2t), 0 ? t ? 8. (a) when is the position function decreasing? (round you

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.

The sun’s mass is 2.0×10^ 30 kg, its radius is 7.0×10 5 km, and it has a rotational period of approximately 28 days. if the sun should collapse into a white dwarf of radius 3.5×10 3 km, what would its period be if no mass were ejected and a sphere of uniform density can model the sun both before and after?