To solve this problem it is necessary to apply the concepts related to Faraday's law and the induced emf.
By definition the induced electromotive force is defined as
Where,
Electric field
B = Magnetic Field
A = Area
At the theory the magnetic field is defined as,
Where,
N = Number of loops
I = current
Permeability constant
We know also that the cross sectional area, is the area from a circle, and the length is equal to the perimeter then
A = \pi r^2
l = 2\pi r
Replacing at the previous equation we have that
Where,
R = Radius of the solenoid
r = The distance from the axis
Re-arrange to find the current in function of time,
Replacing our values we have
Answer:
It is A
Explanation:
At year six more land became avaliable this is the only way that the population could grow so fast and it is correct on edg.
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Answer:</h3>
375 N
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Explanation:</h3>
Topic tested: Newton's Law of motion
The question is testing on the application of Newton's second Law of motion.
We are given;
- Mass of the football = 5 Kg
- Initial velocity of the football, Vf = 15 m/s
- Time taken to bring the ball to rest = 0.2 s
- Final velocity, Vo = 0 m/s ( since the ball went to rest)
We are required to determine the force exerted to bring it to rest.
- According to the Newton's second law of motion the resultant force and rate of change in momentum are directly proportion.
Thus;
Force = 375 N
Hence, the force exerted on the ball by the receiver was 375 N
At the top of the mountain, when he tightens the cap onto the bottole, there is some water and some air inside the bottle. Then he brings the bottle down to the base of the mountain.
The pressure on the outside of the bottle is greater than it was when he put the cap on. If anything could get out of the bottlde, it would. But it can't . . . the cap is on too tight. So all the water and all the air has to stay inside, and anything that can get squished into a smaller space has to get squished into a smaller space.
The water is pretty much unsquishable.
Biut the air in there can be <em>COMPRESSED</em>. The air gets squished into a smaller space, and the bottle wrinkles in slightly.
