Q. A ball is thrown vertically upwards with a speed of $10 \,m \,s ^{-1}$ from the top of a tower 200 m high and another is thrown vertically downwards with the same speed simultaneously. The time difference between them in reaching the ground in seconds is (Take $\left.g=10 \,m\, s ^{-2}\right)$
Motion in a Straight Line
Solution: