<u>Answer:</u> The Young's modulus for the wire is 
<u>Explanation:</u>
Young's Modulus is defined as the ratio of stress acting on a substance to the amount of strain produced.
The equation representing Young's Modulus is:
where,
Y = Young's Modulus
F = force exerted by the weight = 
m = mass of the ball = 10 kg
g = acceleration due to gravity = 
l = length of wire = 2.6 m
A = area of cross section = 
r = radius of the wire = 
(Conversion factor: 1 m = 1000 mm)
= change in length = 1.99 mm = 
Putting values in above equation, we get:
Hence, the Young's modulus for the wire is
A seesaw remains stationary when two students of equal weight sit on the ends
c
Answer:
2.74
Explanation:
Magnification = image distance/object distance
Mag = v/u
Given
v = 46cm
u = 16.8
Magnification = 46/16.8
Magnification = 2.74
Hence the magnification is 2.74
Question:
What two forces are balanced in what we call gravitational equilibrium?
A) the electromagnetic force and gravity
B) outward pressure and the strong force
C) outward pressure and inward gravity
D) the strong force and gravity
E) the strong force and kinetic energy
Answer:
The correct answer is C) Outward Pressure and Inward gravity
Explanation:
Gravitational equilibrium is a balance between the inward pull of gravity and the outward push of internal gas pressure. It also refers to the condition of a star in which the weight of overlying layers at each point is balanced by the total pressure at that point.
As the weight increases in the lower layers of the sun, the pressure also increases to maintain this balance. So you find that the outward push of pressure balances the inward pull of gravity thus creating an equilibrium.
Why is gravitational equilibrium important?
The simple answer is <u>balance. </u> If for instance the sun as a stable star (which has gravitational equilibrium) loses it's balance, it becomes highly unstable and prone to violent outbursts. These outbursts are caused by the very high radiation pressure at the star's upper layers, which blows significant portions of the matter at the "surface" into space during eruptions that may rage for several years. Of course such a condition is adverse to the existence and support of life.
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