REALLY NEED HELP ASAP
Student 1 drops a ball from a tower. Student 2 throws a ball down at 35 m/s from the same height and from the same tower. The student 2's ball takes one-quarter of the time of the dropped ball. What is the height of the tower? Use a=10.0m/s2 [down]

On a horizontal frictionless surface, a small block with mass 0.200 kg has a collision with a block of mass 0.400 kg. immediately after the collision, the 0.200 kg block is moving at 12.0 m/s in the direction 30° north of east and the 0.400 kg block is moving at 11.2 m/s in the direction 53.1° south of east. use coordinates where the +x-axis is east and the +y-axis is north.(a) what is the total kinetic energy of the two blocks after the collision (in ) what is the x-component of the total momentum of the two blocks after the collision? (indicate the direction with the sign of your ) what is the y-component of the total momentum of the two blocks after the collision? (indicate the direction with the sign of your answer.)