Awanita is placing items on a shelf that is 200 cm above the ground. She exerts a force of 20 N to lift a box from the floor to the shelf. She does this in 5 s.

What is Awanita's power output? (Power: [tex]$P = W / t$[/tex])

A. 4 W
B. 8 W
C. 40 W
D. 800 W



Answer :

To determine Awanita's power output, let's follow a step-by-step calculation process using the given data.

### Step 1: Understanding the problem
Awanita lifts a box with:
- Force ([tex]\( F \)[/tex]) = 20 Newtons (N)
- Height ([tex]\( h \)[/tex]) = 200 centimeters (cm)
- Time ([tex]\( t \)[/tex]) = 5 seconds (s)

### Step 2: Convert height to meters
Since the SI unit for height in these calculations is meters (m), we need to convert the height from centimeters to meters:
[tex]\[ 200 \, \text{cm} = 2 \, \text{m} \][/tex]

### Step 3: Calculate Work Done
Work done ([tex]\( W \)[/tex]) can be calculated using the formula:
[tex]\[ W = F \times d \][/tex]
Here, [tex]\( d \)[/tex] is the distance in meters.
[tex]\[ W = 20 \, \text{N} \times 2 \, \text{m} = 40 \, \text{Joules (J)} \][/tex]

### Step 4: Calculate Power Output
Power output ([tex]\( P \)[/tex]) is calculated using the formula:
[tex]\[ P = \frac{W}{t} \][/tex]
Using the work done and the time given:
[tex]\[ P = \frac{40 \, \text{J}}{5 \, \text{s}} = 8 \, \text{Watts (W)} \][/tex]

### Conclusion
Awanita's power output is:
[tex]\[ 8 \, \text{W} \][/tex]

So, the correct answer is:
[tex]\[ \boxed{8 \, \text{W}} \][/tex]