Question

The acceleration due to gravity on a planet is 1.96 m per second square

Answer 1

it would me Mercury or venus

Answer 2

Initial velocity = u = 0
acceleration = 9.8
vertical distance = 3m
final velocity = v = 0

so,
v² - u²= 2as

v² - 0 = 2 x 9.8 x 3
v= 7.7

in the 2nd situation;
u = 0
v= √58.8
a= 9.8

applying the same formula

58.8 - 0 = 2 x 9.8 x s
s = 1.5 m