It would be option C. It rotates, or spins, on its axis, but it revolves around the sun.
Answer:D
Explanation:according to the law of conservation of energy/momentum, when two bodies collides, their total momentum and energy before and after collision are equal. Given that the two bodies move with the same velocities after collision, means that the law has not been violated since momentum = mass x velocity (where mass is constant)
As temperature decreases, the steel will contract (volume decreases) thereby, an increase in Density.
Answer:
Photons strike the CD 
Explanation:
First of all, it is necessary to calculate the energy produced by a semiconductor laser for 69 minutes:


Next, it is possible to calculate the number of photons striking the CD surface during this time:

long in CD
light velocity
Solve to n'


Answer:
M = 175 kg
Explanation:
In the resolution of the harmonic oscillator movement of a system and a mass with a spring, the angular velocity is
w = √ k / m
Where k is the spring constant and m the mass
In this case the mass is the mass of the chair (m) plus the mass of the astronaut (M)
M all = m + M
The angular velocity and the period are related by
w = 2π / T
Substituting
2π / T = √(k/(m + M))
We calculate the astronaut's mass
4π² / T² = k / (m + M)
M = k T² / 4π² - m
M = 569 3.6² /(4π²) - 11
M = 186.8 - 11
M = 175 kg