<span>Since forces are vector quantities, we must indicate direction using positive and negative values. East will be assigned positive and west will be negative. Friction will act as a negative force since it impedes action. To calculate the net force we sum the vector quantities, as follows. Net force equals 50n which is derived by the following calculation: 300n-220n-30n.</span>
This shifts the star’s spectral lines toward the blue end of the spectrum. If the star is moving away from us, it’s waves are effectively stretched out when they reach earth, increasing their wavelength. This shifts the star’s spectral lines toward the red end of the spectrum.
Answer: 
<u>Explanation:</u>
A linear equation is of the form: y = mx + b where
- m is the slope
- b is the y-intercept (where it crosses the y-axis)
x + 4y = 16
4y = -x + 16


The y-intercept (b) = 4
Next, find the slope given point (4, 5) and b = 4

Answer:
.
Explanation:
The average kinetic energy per molecule of a ideal gas is given by:

Now, we know that 
Before the absorption we have:
(1)
After the absorption,
(2)
If we want the ratio of v2/v1, let's divide the equation (2) by the equation (1)




Therefore the ratio will be 
I hope it helps you!