29.5 days
It takes 27 days, 7 hours, and 43 minutes for our Moon to complete one full orbit around Earth. This is called the sidereal month, and is measured by our Moon's position relative to distant “fixed” stars. However, it takes our Moon about 29.5 days to complete one cycle of phases (from new Moon to new Moon).
Answer:
It is important to be able to separate mixtures to obtain a desired component from the mixture and to be able to better understand how each component.
Explanation:
Answer:
3 photons
Explanation:
The energy of a photon E can be calculated using this formula:
Where 
corresponds to Plank constant (6.626070x10^-34Js), 
is the speed of light in the vacuum (299792458m/s) and 
is the wavelength of the photon(in this case 800nm).
Tranform the units
The band Gap is 4eV, divide the band gap between the energy of the photon:
Rounding to the next integrer: 3.
Three photons are the minimum to equal or exceed the band gap.
Answer:
d. It is equal to the component of the gravitational force acting down the ramp.
Explanation:
The stationary crate is inclined at an angle with the horizontal. The Recall, Frictional Force is any Force that opposes motion.
Because the Force of Friction that is opposing the motion of the crate along the inclination side.
Therefore this Frictional force is balanced or equal to the force that is driving the inclined force.
Hence Frictional Force is equal to the Gravitational Force that is acting in the ramp, that is why the crate is stationery.
