
P = Power
W = Work
Delta T = Change of Time
So:
P = 35 Joules
Delta T = 70 secs
W = ?

* Joule/Sec = Watt
Answer: The power used to do this task was 0.5 Watts.
.Answer:
The value of the work done is
.
Explanation:
When a charged particle having charge
is moving through an electric field
, the net force (
) on the charge is

and the work done (
) by the particle is

Given,
.
Substitute the value of electric field in equation (1) and then substitute the result in equation (2).
![W &=& \int\limits^7_0 {q\dfrac{A_{0}}{x^{1/2}}} \, dx \\&=& qA_{0} \int\limits^7_0 {x^{-1/2}} \, dx \\&=& 2qA_{0}[x^{1/2}]_{0}^{7}\\&=& 5.29 qA_{0}](https://tex.z-dn.net/?f=W%20%26%3D%26%20%5Cint%5Climits%5E7_0%20%7Bq%5Cdfrac%7BA_%7B0%7D%7D%7Bx%5E%7B1%2F2%7D%7D%7D%20%5C%2C%20dx%20%5C%5C%26%3D%26%20qA_%7B0%7D%20%5Cint%5Climits%5E7_0%20%7Bx%5E%7B-1%2F2%7D%7D%20%5C%2C%20dx%20%5C%5C%26%3D%26%202qA_%7B0%7D%5Bx%5E%7B1%2F2%7D%5D_%7B0%7D%5E%7B7%7D%5C%5C%26%3D%26%205.29%20qA_%7B0%7D)
Answer:
540 J
Explanation:
U at top equals to K at bottom if it's an isolated system therefore U at top is equals to 540 J so we can assume that at 0m U=0 (mgh) therefore the box has gained some velocity due to the acceleration due to g and we can calculate it using 1/2mv²