Question

What is the ratio of the electric force to the gravitational force between a proton and an electron separated by 5.3*10^-11m ( the radius of a hydrogen atom )

Answer 1

A balloon rising vertically up with a uniform velocity 15 m s releases a ball at a height of 100 m. Calculate

the time taken by the ball to hit the ground ? g = 10 ms

pls help me to solve out.