Answer:
Frequency
Explanation:
Photons are the packet of energy. They are massless and chargeless particles. They travel in the vacuum with the speed of light. The energy of photon is given by :

Where
h = Planck's constant
= frequency of photon
Or 
c = speed of light
= wavelength of photon
From the above equation, it is clear that the energy of photon is directly proportional to its frequency.
D. The osculations show a variable rate of motion. Hope this helps:)
Answer:
Stationary
20N
Explanation:
From the graph, we see that the body traveling is on a fixed position. Therefore, it is a stationary body.
The graph given is a position - time curve.
This curve depict a body changing position with given time.
Since the line of the curve is on a single position, the body is not changing position with the passage of time therefore, it is a stationary object.
B. 20N
From Newton's third law of motion we understand that "action and reaction force are equal but oppositely directed".
Since the person is exerting a force of 20N on the balance.
So, the reaction force by the balance is 20N upward.
Answer:
2.5 m/s
Explanation:
There are calculators online that can help you easily calculate the accerlation.