Let’s solve each problem step by step.
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Problem 1: Joseph sweeping leaves
We are told:
- Force (F) = 2.0 N
- Distance (d) = 3 meters
- Time (t) = 12 seconds
Step 1: Calculate Work
Work is calculated using the formula:
>
W = F × d
Plug in the numbers:
> W = 2.0 N × 3 m =
6 Joules
✔ So, mechanical work performed =
6 J
Step 2: Calculate Power
Power is calculated using the formula:
>
P = W / t
We just found W = 6 J, and t = 12 s
> P = 6 J ÷ 12 s =
0.5 Watts
✔ So, power used =
0.5 W
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Problem 2: Tractor pulling hay wagon
We are told:
- Force (F) = 500 N
- Distance (d) = 2000 meters
- Time (t) = 5 minutes → but we need time in
seconds for power calculation!
Convert minutes to seconds:
> 5 minutes × 60 seconds/minute =
300 seconds
Step 1: Calculate Work
Again, use:
>
W = F × d
> W = 500 N × 2000 m =
1,000,000 Joules
✔ So, work performed =
1,000,000 J (or 1 million Joules)
Step 2: Calculate Power
Use:
>
P = W / t
> P = 1,000,000 J ÷ 300 s ≈
3333.33 Watts
You can round it if needed — let’s keep it as
3333.33 W, or write it as a fraction: 1000000/300 = 10000/3 ≈ 3333.33
✔ So, power used =
3333.33 W
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Final Answer:
Problem 1:
- Mechanical work =
6 Joules
- Power =
0.5 Watts
Problem 2:
- Work performed =
1,000,000 Joules
- Power used =
3333.33 Watts
Parent Tip: Review the logic above to help your child master the concept of calculating work and power worksheet.
