Friction is the opposition offered to the movement of a surface on another and depends on the nature of the surfaces in contact.
<h3>What is friction?</h3>
The term friction refers to the opposition that is offered by surfaces in contact when they move over each other. The question is incomplete but I will try to help you the much I can.
Now recall that fricton only depends on the nature of the surfaces in contact. The friction is te reason when heat is provides in the moving parts of machines.
Learn more about friction: brainly.com/question/15117038
Answer : <u>Natural</u>
Explanation : Natural resources are the resources that are found in the environment and are developed without the intervention of humans
Answer:
The current drawn by the motor from the line is 4.68 A.
Explanation:
Given that,
Internal resistance of the dc motor, r = 3.2 ohms
Voltage, V = 120 V
Emf in the motor, 
We need to find the current drawn by the motor from the line. A dc motor with its rotor and field coils connected in series, applying loop rule we get :
I is current drawn by the motor
So, the current drawn by the motor from the line is 4.68 A. Hence, this is the required solution.
Sound source is at rest, you are moving with velocity v, f = frequency, c = speed of sound:
f = f0(1 + v/c)
115 = 100(1 + v/343)
115 = 100 + 100v/343
15 = 100v/343
v = 15*343/100
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v = 51,45 m/s </span>
