Missing part in the text of the problem:
"<span>Water is exposed to infrared radiation of wavelength 3.0×10^−6 m"</span>
First we can calculate the amount of energy needed to raise the temperature of the water, which is given by

where
m=1.8 g is the mass of the water

is the specific heat capacity of the water

is the increase in temperature.
Substituting the data, we find

We know that each photon carries an energy of

where h is the Planck constant and f the frequency of the photon. Using the wavelength, we can find the photon frequency:

So, the energy of a single photon of this frequency is

and the number of photons needed is the total energy needed divided by the energy of a single photon:
Answer:
Flow rate 2.34 m3/s
Diameter 0.754 m
Explanation:
Assuming steady flow, the volume flow rate along the pipe will always be constant, and equals to the product of flow speed and cross-section area.
The area at the well head is

So the volume flow rate along the pipe is

We can use the similar logic to find the cross-section area at the refinery

The radius of the pipe at the refinery is:



So the diameter is twice the radius = 0.38*2 = 0.754m
ZC. The forward force of the surfboard's acceleration is balanced by the backward force of the surfer's mass.
Answer: The Articles of Confederation were against having a strong central government.
Explanation:
D. Redefine the machine’s system boundaries.
The Law of Conservation of Energy states that energy can't be created not destroyed. Energy, however, can be changed from one form to another. The law applies to isolated systems only. By redefining and expanding the system (including all factors affecting it) , the machine's ability to do work should improve.