den pushes a desk 400 cm across the floor. he exerts a force of 10 n for 8 s to move the desk. what is his…

den pushes a desk 400 cm across the floor. he exerts a force of 10 n for 8 s to move the desk. what is his power output? (power: p = w/t)\n1.25 w\n5 w\n40 w\n500 w

den pushes a desk 400 cm across the floor. he exerts a force of 10 n for 8 s to move the desk. what is his power output? (power: p = w/t)\n1.25 w\n5 w\n40 w\n500 w

Answer

Answer:

B. 5 W

Explanation:

Step1: Convert distance to SI unit

$400\ cm = 4\ m$

Step2: Calculate work done

$W = F\times d$, where $F = 10\ N$ and $d = 4\ m$. So $W=10\times4 = 40\ J$.

Step3: Calculate power

$P=\frac{W}{t}$, with $W = 40\ J$ and $t = 8\ s$. Then $P=\frac{40}{8}=5\ W$.