Answer:
1.628 
Explanation:
Anywhere in the universe, In a closed system, <u>Conservation of energy</u> is applicable.
In this case
Neil is initially on the surface of moon and has a velocity of 1.51
in upward direction.
⇒He has Kinetic energy=
=
J
But with respect to the surface of the moon,
where m=mass of moon
v=velocity of Neil
He has Potential energy=
=0 J
At the highest point of his jump, his velocity =0
⇒ Kinetic energy=
=0 J
His Potential energy with respect to the surface of moon=
=
where m=mass of moon
g= gravitational acceleration on moon
h=height from moon's surface
By Conservation Energy Principle
+
=
+
+0=0+
= 
= 
J= 
⇒ g =
= 1.628 