Question

A stone is dropped from a building and 2 seconds later another stone is dropped.How far apart are these two stones by the time the first one has reached at speed of 30 ms^-1

Answer 1

For mass A,

v = u + gt

30 = 10t

t = 3 sec

For mass A, distance travelled in 3 sec is,

s = 0 + 1/2 gt²

s = 1/2x10x9 = 45 m

For mass B distance travelled in 1 sec,

s ' = 0 + 1/2x10x1 = 5

Separation between them = 45 - 5 = 40 m