Please Help? A cannonball is shot horizontally. It remains in the air for 5s and its range is 20m. If its launch velocity is doubled, for how long does it remain in the air?
a.20s
b.2.5s
c.5s
d.10s

waves moving from a fast medium to a slow medium will experience a reflection as light travels more slowly than red light. total internal reflection occurs when the critical angle is.

force required to detach it is given by

charges are taken to be fundamental charge

now we have

so above is the minimum distance at which it will detach