Answer:
B. 81
Explanation:
When you multiply two numbers, round the answer to the least number of significant figures available. 67.6 has three significant figures, and 1.2 has two significant figures. So we round to two significant figures.
Answer:
One may assume that the planet radiates energy like a blackbody at some temperature according to the Stefan–Boltzmann law. Thermal equilibrium exists when the power supplied by the star is equal to the power emitted by the planet. The temperature at which this balance occurs is the planetary equilibrium temperature.
Explanation:
What are the answer choices, if there are any?
Answer:
a) 6.9*10^14 Hz
b) 9*10^-12 T
Explanation:
Given that
The wavelength of the wave, λ = 435 nm
Amplitude of the electric field, E(max) = 2.7*10^-3 V/m
a)
The frequency of the wave can be found by using the formula
c = fλ, where c = speed of light
f = c/λ
f = 3*10^8 / 435*10^-9
f = 6.90*10^14 Hz
b)
E(max) = B(max) * c, magnetic field amplitude, B(max) =
B(max) = E(max)/c
B(max) = 2.7*10^-3 / 3*10^8
B(max) = 9*10^-12 T
c)
1T = 1 (V.s/m^2)
Answer:
1143 N at 1.59 m from the left end
Explanation:
For the system to produce equilibrium, the total force and moment must be 0. Since the total weight downward is
481 + 381 + 281 = 1143 N
Therefore the magnitude of the force acting upward to balance this system must be the same of 1143 N
That alone is not enough, we also need the position of the force for the total moment to be 0.
Let x be the length from the this upward force to the left side. And let the left point be the point of reference for moment arm:
481 * 3.32/2 + 381 * 0.8798 + 281*(3.32 - 0.8798) - 1143*x = 0
x = (481*1.66 + 381 * 0.8798 + 281*2.4402)/1143 = 1.59m
