Answer
The power for the select value of $R$ from $0$ to $20$ $ohms$:
If $R$ $=$ $0$ , $P$ $=$ $80$ $watts$
If $R$ $=$ $3$ , $P$ $=$ $50$ $watts$
If $R$ $=$ $5$ , $P$ $=$ $40$ $watts$
If $R$ $=$ $11$ , $P$ $=$ $25$ $watts$
If $R$ $=$ $15$ , $P$ $=$ $20$ $watts$
If $R$ $=$ $20$ , $P$ $=$ $16$ $watts$
Work Step by Step
Given the resistance and voltage, we can easily solve for the power by using the below formula:
$ Power $ $ (P) $ $=$ $\frac{Voltage (V)^{2}}{Resistance(R)}$
$ Power $ $ (P) $ $=$ $\frac{20^{2}}{5 + R}$
By using the formula above, the following is the power for the select value of $R$ from $0$ to $20$ $ohms$:
If $R$ $=$ $0$ , $P$ $=$ $80$ $watts$
If $R$ $=$ $3$ , $P$ $=$ $50$ $watts$
If $R$ $=$ $5$ , $P$ $=$ $40$ $watts$
If $R$ $=$ $11$ , $P$ $=$ $25$ $watts$
If $R$ $=$ $15$ , $P$ $=$ $20$ $watts$
If $R$ $=$ $20$ , $P$ $=$ $16$ $watts$
