PART A)
As we know that energy of light depends on its wavelength and frequency as following formula

now we know that wavelength of blue light is less than the red light so here energy of blue light will be more
also we know that

so here if wavelength is smaller for blue light so its frequency will be high and the speed of both light will be same in same medium
PART B)
Since we know that frequency of blue light is more than red light as well as wavelength of blue light is less than the wavelength of blue light so here blue light will have more energy
When blue light and red light strike the metal surface then due to more energy of blue light it will release some loosely bonded electrons from metal surface which will contribute in current.
here if we increase the intensity of light then the number of photons that contain the blue light of certain energy will be more and that will contribute more current
So here quantification help as we know that due to quantization only certain frequency or energy will lead to eject electron so all colours will not give this current
Question:
A 63.0 kg sprinter starts a race with an acceleration of 4.20m/s square. What is the net external force on him? If the sprinter from the previous problem accelerates at that rate for 20m, and then maintains that velocity for the remainder for the 100-m dash, what will be his time for the race?
Answer:
Time for the race will be t = 9.26 s
Explanation:
Given data:
As the sprinter starts the race so initial velocity = v₁ = 0
Distance = s₁ = 20 m
Acceleration = a = 4.20 ms⁻²
Distance = s₂ = 100 m
We first need to find the final velocity (v₂) of sprinter at the end of the first 20 meters.
Using 3rd equation of motion
(v₂)² - (v₁)² = 2as₁ = 2(4.2)(20)
v₂ = 12.96 ms⁻¹
Time for 20 m distance = t₁ = (v₂ - v ₁)/a
t₁ = 12.96/4.2 = 3.09 s
He ran the rest of the race at this velocity (12.96 m/s). Since has had already covered 20 meters, he has to cover 80 meters more to complete the 100 meter dash. So the time required to cover the 80 meters will be
Time for 100 m distance = t₂ = s₂/v₂
t₂ = 80/12.96 = 6.17 s
Total time = T = t₁ + t₂ = 3.09 + 6.17 = 9.26 s
T = 9.26 s
Given that the rope is not moving (acceleration is zero), by the second Law of Newton (F=m*a), the net force acting on the rope is zero.
Then, the force applied by the team B equals the force applied by the tema A: 103 N.
A voltmeter is the instrument used to measure a potential difference between two points in an electric circuit
IV - Temperature
DV - Light intensity