Question

A ball is thrown vertically upward with an initial velocity of 30 M per second find maximum reach height reached by the body take G is equal to 10 M per second square

Answer 1

$v {}^{2} - u {}^{2} = 2as$
velocity at the highest point will be 0
$u {}^{2} = 2gh$
-ve sign is removed bcz g will be -ve in upward direction
30×30=2×10×h
h=900/20
h=45 m

Answer 2

initial velocity is 30m/s
final velocity is 0m/s
g= -10m/s (its acting against gravity)

v^ 2= u2 + 2gs
30^2 +2*-10*s
900 -20s
s= -900/-20
s= 45m.