Answer:
I literally just learned this last week and if I remember correctly it is Faraday's Law of Induction.
Explanation: Hope this helps also I hope you have/had an amazing day today<3
Explanation:
Let are the number of turns in primary and secondary coil of the transformer such that,
A resistor R connected to the secondary dissipates a power
For a transformer,
...............(1)
The power dissipated through the secondary coil is :
.............(2)
Let are the new number of turns in primary and secondary coil of the transformer such that,
New voltage is :
...............(3)
So, new power dissipated is
So, the new power dissipated by the same resistor is 6400 watts. Hence, this is the required solution.
Here As we can see the figure that the end of the rope is pulled by some force F
Now as we can see that Piano is connected by a pulley which is passing over the pulley so effectively net force on the piano upwards will be 2F as it is connected by 2 ropes by the pulley
Now for constant velocity of the piano we will say
since velocity is constant so acceleration must be ZERO
so here we have
as we know here that
mg = 1000 N
so we will have
so here force must be 500 N