100/2.5 is 40.
40 is the energy that is being produced
A photoelectric cell is an electronic device which is used to convert light energy into electric energy.The operation of this device is based on photoelectric effect.
Light of suitable frequency i.e greater or equal to threshold frequency will fall on the cathode maintained at negative potential.The electron emission will take place and these electrons are drifted towards the anode which is at positive potential.
Here,only those radiations will be capable of emitting electrons irrespective of surface barrier of metals whose energy is greater than the work function.
We know that the radiation having long wavelength has least energy as energy and wavelength are inversely proportional to each other.

Here h is the Planck's constant,c is the velocity of light.
Here we have been given red light and blue light.
In the visible spectrum of radiation, the red light has longer wavelength than all other colors of light.Hence blue light has more energy as it's wavelength is less as compared to red light.
Hence, the blue light will activate the most and red the least.
Answer
given.
Mass of big fish = 15 Kg
speed of big fish = 1.10 m/s
mass of the small fish = 4.50 Kg
speed of the fish after eating small fish =?
a) using conservation of momentum
m₁v₁ + m₂v₂ = (m₁+m₂) V
15 x 1.10 + 4.50 x 0 = (15 + 4.5)V
16.5 = 19.5 V
V = 0.846 m/s
b) Kinetic energy before collision


KE₁ = 9.075 J
Kinetic energy after collision

KE₂ = 6.98 J
Change in KE = 6.98 - 9.075 = -2.096 J
hence,
mechanical energy was dissipated during this meal = -2.096 J
The centripetal force (of gravity) on a satellite in orbit is an
unbalanced force (because there's no equal force pulling
the satellite away from Earth), changes the direction of the
satellite (into a closed orbit instead of a straight line), and
always acts toward the center of whatever curve the satellite
happens to be on at the moment.
Answer:
1.78 rad/s
1.70344 rad/s
Explanation:
v = Velocity = 0.8 m/s
m = Mass of person = 60 kg
= Distance between center of mass of person and pole = 0.45 m
= New distance between center of mass of person and pole = 0.46 m
I = Moment of inertia
Angular speed is given by

The angular speed is 1.78 rad/s
In this system the angular momentum is conserved

The new angular speed is 1.70344 rad/s