Question

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)

a. 1.25 W
b. 5 W
c. 40 W
d.500 W

Answer 1

We Know, P = W/t
P = F * s/t
Here, F = 10N
s = 400cm = 4m
t = 8 sec.

Substitute their values in to expression,
P = 10 * 4/8
P = 10 * 1/2
P = 5 Watt

So, your final answer is 5 W

Hope this helps!

Answer 2

Answer: The correct option is Option b.

Step-by-step explanation:

Power is defined as the rate of work done by an object.

Mathematically,

`P=(W)/(t)` .....(1)

And work done is the product of force exerted on the object times the displacement covered by that object.

Mathematically,

`W=F.s`

Putting this value in above equation, we get:

`P=(F.s)/(t)`

where,

P = power = ?W

F = Force exerted = 10N

s = Displacement = 400cm = 4m (Conversion factor: 1m = 100 cm)

t = Time taken = 8s

Putting values in above equation, we get

`P=(10* 4)/(8)\\\\P=5W`

Hence, the correct option is Option b.