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
Answer:
The period of the system of ladder and woman, T = 2.5 seconds
Explanation:
Mass of the ladder,
Mass of the artiste,
Length of the ladder, L = 42.0 kg
The total moment of inertia can be calculated using the equation:
D = L/2 = 3/2
D = 1.5 m
The frequency of the system of ladder and woman follows that of a physical pendulum which can be given by the equation:
The period of the system of ladder and woman is given by:
T = 1/f
T = 1/0.4
T = 2.5 seconds
Answer:
Distance covered is: 45 meters
Displacement is 15 meters to the right of where he started
Explanation:
Notice that Brady has walk a path that looks like an incomplete rectangle of height 5 meters and length 25meters, although he actually didn't cover the full length (25 meters) when getting back to the point where he started (he made just 10 meters instead of 25 after the third turn right) See attached image.
Therefore, Brady's displacement is 15 meters to the right of where he started, and the total distance he covered is :
Distance = 5m + 25m + 5m + 10m = 45m
