He should push it gently.
This is because the forces of resistance this situation are minimal, so the rock will not slow as it would on Earth. Kicking the rock may result in it travelling too fast and hitting something else, causing damage. Moreover, the rock could start rebounding off of surfaces and create havoc.
Answer:
1. telescope
2.

f- focal length
f- focal length r- the radius of curvature of the mirror

p-the distance of the object from the vertex of the mirror
l-the distance of the figure from the vertex of the mirror
Answer:
Protons = 50
Mass number = 119
Explanation:
A neutral of tin, Sn, has a Z value of 50 and neutrons are 69.
Z is the atomic number. The atomic number is equal to number of protons or number of electrons in an atom that is neutral i.e:
Z = PROTONS = ELECTRONS
So the number of protons = 50 since Z is 50
>>>>>>>>>>>>>>>¦
The bulk of the mass of an atom is concentrated in the nucleus. To calculate mass number, we simply sum all the elementary particles in the nucleus i.e protons and neutrons. These particles are called the nucleons.
Mass number (A) = P + N
= 50 + 69
= 119