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:
No. The protostellar cloud spins faster in the collapsing stage (stage 1) and becomes much slower in the contraction stage (stage 2)
Explanation:
Once the cloud is so dense that the heat which is being produced in its center cannot easily escape, pressure rapidly rises, and catches up with the weight, or whatever external force is causing the cloud to collapse, and the cloud becomes stable, as a protostellar cloud.
The protostellar cloud will become more dense over thousands of years. This stage of decreasing size is known as a contraction, rather than a collapse. In the contraction stage the cloud has become much slower, and because weight and pressure are more or less in balance. In the first stage of formation, the decrease of size is very rapid, and compressive forces completely overwhelm the pressure of the gas, and we say that the cloud is collapsing.
Answer:
False.
Explanation:
Backbone Cabling: A system of cabling that connects the equipment rooms and telecommunications rooms.
Horizontal Cabling: The system of cabling that connects telecommunications rooms to individual outlets or work areas on the floor.
Answer:

Explanation:
From the question we are told that:
Number of battery 
Voltage source
Lamp Power
Generally the equation for Resistance is mathematically given by



Therefore


Generally the equation for Current is mathematically given by


