Answer:
The answer is A
Explanation:
Here's an example. A child is in school taking a test. They have made a mistake on a question, and want to erase it. The eraser is made out of a type of rubber, the rubber has friction, which means the eraser has something that's going to resist movement. Now the child has exerted enough force to get it moving, and it's moving, it won't stop unless the child stops exerting force to keep it moving. Both Newton's 1st and 3rd law explain the action of moving something on a surface with friction.
Answer:
w = 0.943 rad / s
Explanation:
For this problem we can use the law of conservation of angular momentum
Starting point. With the mouse in the center
L₀ = I w₀
Where The moment of inertia (I) of a rod that rotates at one end is
I = 1/3 M L²
Final point. When the mouse is at the end of the rod
= I w + m L² w
As the system is formed by the rod and the mouse, the forces during the movement are internal, therefore the angular momentum is conserved
L₀ = L_{f}
I w₀ = (I + m L²) w
w = I / I + m L²) w₀
We substitute the moment of inertia
w = 1/3 M L² / (1/3 M + m) L² w₀
w = 1 / 3M / (M / 3 + m) w₀
We substitute the values
w = 1/3 / (1/3 + 0.02) w₀
w = 0.943 w₀
To finish the calculation the initial angular velocity value is needed, if we assume that this value is w₀ = 1 rad / s
w = 0.943 rad / s
Answer: 
Energy is directly proportional to the frequency.
The energy of a photon is given by:

Where, E is the energy and
is the frequency.
Frequency of the radio wave is given:


Multiply the above two:
Energy,

Hence, the energy of each photon of radio wave having frequency
is 
Answer:
The letter "x" is often used in algebra to mean a value that is not yet known
Explanation: