A cart of mass m1 = 10 kg slides down a frictionless ramp and is made to collide with a second cart (initially at rest) of mass m2 = 20 kg, which then heads into a vertical loop of radius 0.25 m as shown in Figure P7.66. Derive the expression of height h, in terms of radius r, from which cart 1 would need to start to make sure that cart 2 completes the loop without leaving the track and, hence, determine the value of h. Assume an elastic collision.

The solar panels used by mark function because of the photoelectric effect. light shines on the cells causing electrons to be ejected from the metal, which produces an electric current. at night on mars, no light will fall on the solar cells and no electric current will be generated. according to your notes, what type of light is typically needed to cause the photoelectric effect? a)visible b)ultraviolet c)infrared

Determine the maximum r-value of the polar equation r =3+3 cos 0

This is important 1. what happens to the speed of molecules in water vapor when it condenses to form a liquid? (2 points) the molecules slow down. the molecules speed up. the molecules slow down and then speed up. the molecules speed up and then slow down. 2. how might human activities change to compensate for a decrease in water supplies? (2 points) humans might build a factory. humans might build drainage systems. humans might extract more water from the ground. human behavior does not change because of the water cycle. i'll be grateful if anyone can answer these 2 questions !