Question

From the top of a tower 100 m in height a ball is dropped and at the same time another ball is projected vertically upwards from the ground with a velocity of 25 m/s. Find when and where the two balls will meet? (g = 9.8 m/s)

Answer 1

For the ball dropped from the top 

x = 4.9 t² …….(i) 

For the ball thrown upwards 

100 – x =25t – 4.9 t² …….(ii) 

From eq. (i) and (ii) 

t = 4s x = 78.4 m.