Astone is projected horizontally with a velocity 9.8 m/s from a tower of height 100m. its velocity after 1sec of projection is

For a shot at some tallness, you should break the speed into two parts horizontal and vertical.

The horizontal part is the underlying speed imparted;ie-9.8m/s.this segment will stay unaltered throughout(since there is no increasing speed the horizontal way)

For your vertical segment, the flight has recently begun!

Taking zero as the underlying vertical speed and gravity as the net quickening downwards, the vertical segment of speed tends to increase at the rate of 9.8 m/s.

So following one moment

Horizontal velocity 9.8m/s

Vertical velocity 9.8m/s

Now all you require is to include the two parts in a vector strategy

So your final answer will be 9.8*√ 2

since v=u+at ,so v= 9.8+9.8×1
gives,= 19.6