Answer:
Explanation:
In a L C R circuit, the average power is given by

As given in the question
CosФ = R / Z
And we know that

So


Answer:
Time taken by A and B is 1.2 hr.
Explanation:
Given that
Time taken by tank when all(A+B+C) are open = 1 hr
Time taken by tank when A+C are open = 1.5 hr
Time taken by tank when B+C are open = 2 hr
If we treat as filling of tank is a work then
Work = time x rate
Lets take work is 1 unit
1 = 1(1/a+1/b+1/c) ---------1
1 = 1.5(1/a+1/c) ----------2
1 = 2(1/b+1/c) --------3
From equation 1 and 3
1=1(1/a+1/2)
a=2
Form equation 2
1 = 1.5(1/2+1/c)
c=6
From equation 3
1 = 2(1/b+1/6)
b=3
So time taken by
A is alone to fill tank is 2 hr
B is alone to fill tank is 3 hr
C is alone to fill tank is 6 hr
So 
Time taken by A and B is 1.2 hr.
Answer:
A. 20 N
Explanation:
Weight of the book = mass × acceleration due to gravity
= 2 × 10
= 20 N
Answer:
It would be PE=16kg * 9.8 m/s^2 * 1m = 160 J
Explanation:
The person who asked this question ended up answering his own question so I'm here to let you know all that the answer was founded by the person whos posted the question himself full credit goes to him :)