If the gravitational force between the electron (of mass 9.11 × 10−31 kg) and the proton (of mass 1.67 × 10−27 kg) in a hydrogen atom is 1.5 × 10−47 N, how far apart are the two par- ticles? The universal gravitational constant is 6.673 × 10−11 N · m2/kg2. Answer in units of m.

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.)