What power in kw is required to transfer a charge of 9000 coulomb through a potential difference of 220 volts in 45 min?
0.9 kw
0.73 kw
0.5 kw
1.6 kw

Explanation:

The work W required for the transfer is equal to the energy difference

where q is the charge we want to transfer and ΔV is the potential difference.

So, the work needed will be

Now, the average power is:

As the Watt is Joule/second, we need the 45 min multiplied by 60:

Taking all this together:

or

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.