Answer:
Doppler effect changes the wavelength of the light emitted, depending upon whether source is moving away or coming towards the observer(detector).
Explanation:
Doppler effect in light is actually a relativistic effect but somewhat similar to the one which happens in sound waves.
When the source is moving away from the detector, the wavelength of the light emitted from the source appears to be increased as seen by the detector, as a result the frequency decreases(we know that frequency of light= speed of light/wavelength of light. Here speed of light is constant and frequency of light is inversely proportional to its wavelength)
Due to this decrease in frequency the light emitted from the source appears more red, since red color is on low frequency side in the electromagnetic spectrum.
Similarly for the source moving towards the detector, the wavelength appears to be decreased, thereby resulting in increase in frequency and the source appears blue. The shift in frequency is known as doppler shift.
The shift in frequency when the source is moving away is known as redshift and the one where the source is moving towards detector is known as blueshift
You'd have an easier time using the equation if you understood where the equation comes from.
The law here ... the major principle to remember, the key, the fundamental truth, the big cookie ... is the fact that momentum is conserved. <em>The total momentum after they join up is the same as the total momentum before they meet.</em>
Momentum of an object is (mass) times (speed).
Now, list all the things you know, before and after the putty meets the ball:
<u>Before:</u><u> </u>There are two objects.
Mass of putty = 3 kg
Speed of putty = 5m/s
Momentum of putty = 3 x 5 = 15 kg-m/s.
Mass of ball = 5 kg
Speed of ball = zero
Momentum of ball = 5 x 0 = zero
Total momentum of both things = 15 kg-m/s
<u>After</u>: There is only one object, because they stuck together.
Mass of (putty+ball) = (3+5) = 8 kg
Speed of (putty+ball) = we don't know; that's what we have to find
Momentum of (putty+ball) = 8 x (speed)
===================================
We know that the momentum after is equal to the momentum before.
8 x (speed) = 15 kg-m/s
Divide each side by 8 :
Speed = 15 / 8 = <em>1.875 m/s </em> after they stick together.
The formula for getting the density of an object is
density = mass/volume = ρ = m/v
mass =42 kg
volume = 22m3
we will work on the equation directly because they are already in there SI units
density = 42 kg/22m3
density = 1.9090909090909
which if rounded can become 1.9 kg/m3
ans = the object's density is 1.9090909090909 kg/m3 or 1.9 kg/m3
Direction, while speed is simply how fast you are moving, velocity is in a specific direction, and you can have negative velocity if you start moving in the opposite direction.