Question

A bullet is fired horizontally with an initial speed of 250 m/s from a 20 m high tower. How long is the bullet in the air?

Answer 1

The bullet has initial vertical velocity `u=0` since it has been fired horizontally. So its normal time of free fall under gravity is the answer.If this time be t sec then
`20= 0xxt+1/2xx10xxt^2`
`:. t =sqrt4=2s`