"Temperature is the measure of the average kinetic energy of the particles in a substance, which is related to how hot or cold that substance is. Historically, two equivalent concepts of temperature have developed, the thermodynamic description and a microscopic explanation based on statistical physics"
This is because of of the heating effect of a current. The glow is a result of current passing through the filament. The current experiences resistance as a result heat is generated. When resistance is at zero, there potential differences is not needed hence temperature generated will be at a constant.
Answer
given,
heat added to the gas,Q = 3300 kcal
initial volume, V₁ = 13.7 m³
final volume, V₂ = 19.7 m³
atmospheric pressure, P = 1.013 x 10⁵ Pa
a) Work done by the gas
W = P Δ V
W = 1.013 x 10⁵ x (19.7 - 13.7)
W = 6.029 x 10⁵ J
b) internal energy of the gas = ?
now,
change in internal energy
Δ U = Q - W
Q = 3300 x 10³ cal
Q = 3300 x 10³ x 4.186 J
Q = 1.38 x 10⁷ J
now,
Δ U = 1.38 x 10⁷ - 6.029 x 10⁵
Δ U = 1.32 x 10⁷ J
Answer:
0.22mm
Explanation:
A far sighted person is a person suffering from long sightedness i.e such individual can only see far distant object clearly but not near distant object. The defect is corrected using convex lens.
Since convex lens is used, the focal (f) length of the lens is positive and the image distance (v) is also positive.
Using the lens formula,
1/f = 1/u + 1/v
Where u is the object distance = 0.35mm
v = 0.6mm
1/f = 1/0.35+1/0.6
1/f = 2.86 + 1.67
1/f = 4.53
f = 1/4.53
f = 0.22mm
The focal length of the contact lenses will be 0.22mm