Answer
given,
height of window = 4 m
time taken to travel = 1 s
acceleration due to gravity = 9.8 m/s²



u = -0.905 m/s
initial velocity of ledge v = 0
now,
v² = u² + 2 a s
(-0.905)² = 0 + 2 × 9.8 ×s
s = 0.042 m
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
When light passes from one medium to another, part of it continues on
into the new medium, while the rest of it bounces away from the boundary,
back into the first medium.
The part of the light that continues on into the new medium is <em>transmitted</em>
light. Its forward progress at any point in its journey is <em>transmission</em>.
Its direction usually changes as it crosses the boundary. The bending is <em>
refraction</em>.
The part of the light that bounces away from the boundary and heads back
into the first medium is <em>reflected</em> light. The process of bouncing is <em>reflection</em>.