Decibel - the decibel is a relative unit of measurement equal to one 10th of a bel
Answer:
Work done by external force is given as

Explanation:
As per work energy Theorem we can say that work done by all force on the car is equal to change in kinetic energy of the car
so we will have

now we have


so from above equation

so from above equation work done by external force is given as

You never gave us an answer, so therefore, we can't answer this question.
Answer:
B/4
Explanation:
The magnetic field strength is inversely proportional to the square of the distance from the current. At double the distance, the strength will be 1/2^2 = 1/4 of that at the original distance:
The field at twice the distance is B/4.
I think Y is the answer to number 4