A ball is thrown downwards with a speed of 20m//s from top of a building 150m high and simultaneously another ball is thrown vertically upwards with a speed of 30m//s from the foot of the building . Find the time when both the balls will meet . (g=10m//s^(2))

A ball is thrown downwards with a speed of 20m//s from top of a buildi

1.	A ball is thrown downwards with a speed of 20m//s from top of a building 150m high and simultaneously another ball is thrown vertically upwards with a speed of 30m//s from the foot of the building . Find the time when both the balls will meet . (g=10m//s^(2))
Answer» Solution :(i)`S_(1)=20t+5t^(2)+S_(2)=30t-5t^(2)` `150=50t` `t=3s`. (II)RELATIVE acceleration of both is zero since both have acceleration in DOWNWARD direction. `veca_(AB)=veca_(A)-veca_(B)=g-g=0` `vecV_(BA)=30-(-20)=50` `S_(BA)=V_(BA)xxt` `t=(S_(BA))/(V_(BA))=(150)/(50)=3s`