Height of the body from the ground can be calculated by using the formula h = – ut + (1/2)gt² in
a) A body projected vertically with velocity 'u' from the top of tower, reaches the ground in 't' sec.
b) A body dropped from a balloon moving up with uniform velocity, reaches the ground in 't' sec
c) A body dropped from a helicopter moving up with uniform velocity, reaches the ground in 't' sec
d) A body projected vertically from the ground reaches the ground in 't' sec.