a)
• P = F/A
P = pressure = 630 N/m^2
F = force
A = area
F = mg = 0.50 kg x 9.8 m/s^2 = 4.9 N
m= mass
g= gravity
P = F/A
A = F/P
A = 4.9 N / 630 N/m^2 = 7.778 x 10^-3 m^2
b)
• Area of a circle = pi* radius ^2
7.778 x 10^-3 m^2 = pi* radius ^2
√(7.778 x 10^-3 m^2 / pi ) = radius
radius = 0.04976 m
Answers:
a ) 7.778 x 10^-3 m^2
b) 0.04976 m
The correct answer is
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C) 1200 g/m3. Let's see why. The relationship between liters and cube decimeters is
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Therefore,
However, we also know that
Therefore,
and
Therefore, the density of the problem
becomes
Answer:
5.327
Explanation:
Stefan-Boltzmann law states that the total radiant heat power emitted from a surface is proportional to the fourth power of its absolute temperature.
W = σT⁴
Where,
W is the total radiant heat power emitted from a surface
σ is constant of proportionality, called the Stefan–Boltzmann constant = 5.67 × 10⁻⁸ Wm⁻²K⁻⁴
T is absolute temperature in kelvin
For the first star, T = 5200 K
∴ W₁ = σ(5200)⁴
For the second star, T = 7900 K
∴ W₂ = σ(7900)⁴
The amount of energy radiated by the hotter star W₂, with respect to the other star W₁ is,
W₂ / W₁ = σ(7900)⁴ / σ(5200)⁴