Question

A body is projected horizontally with speed 20 m per second what will be its speed after 5 seconds

Answer 1

Since, body is projected horizontally with a velocity of 20m/s.

ux = 20m/s

ax = 0

So, vx = 20m/s for all time.

Along vertical axis,

uy = 0

t = 5

ay = 10m/s2

vy =?

vy = uy +ayt

=> vy = 0 + 10*5= 50m/s

So, magnitude of velocity of body after 5s

√{(50)²+(20)²}m/s
=√2900 m/s
=53.851 m/s
= 54 m/s (approx)

Answer 2

Ah kinematics. That takes me back. If the body is not far off the ground, the answer is zero.

But if it filled with helium, the answer is a little ways in the wind direction and mainly straight up but undetermined.

But seriously, you shouldn't be digging up bodies and throwing them around to test the laws of gravity.