Solution:
Given,
Initial velocity (u) = 5 m/s,
Time take (t) = 2 seconds,
Acceleration (a) = g = 10 m/s2
Height (h) = ?
Final velocity (v) = ?
Now using the second equation of motion we get,
\(s=ut+\frac12at^2\)
Or, \(h=ut+\frac12gt^2\)
Or, \(h=5\times2+\frac1210\times(2)^2\)
Or, \(h=5\times2+5\times4\)
∴ h = 30 m
Also, using the first equation of motion we get,
v = u + at
= u + gt
= 5 + 10 × 2
= 5 + 20
= 25 m/s
Hence, the height is 30 m and the stone strikes the ground with the velocity of 25 m/s
