Question

Calculate the power, in watts, needed to mow a lawn in 50 minutes if the work required is 500,000J. (round your answer to 2 decimal places)

Answer 1

Given:

• Work = 500,000J
• Time = 50 min = 50 × 60 = 3000 s

To find:

• Power

Solution:

Power is the rate of doing work or work per unit time.

♦ Power = Work/Time

Putting the values,

➾ Power = 500,000/3000

➾ Power = 500/3

➾ Power = 166.67 J/s or 166.67 W

Therefore, the power, in watts, needed to mow a lawn = 166.67 W

Bigger Units of Power:

• 1 kilowatt (kW) = 10³ W
• 1 Megawatt (MW) = 10⁶ W
• 1 Gigawatt (GW) = 10⁹ W
• 1 Horse Power (HP) = 746 W ≈ 750 W (approx)

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Answer 2

Answer:

166.66 W

Explanation:

Given that if the work required is 500,000J and time is 50 minutes. Then the power in watts is.

Power is defined as work done per unit time.

Power = (Work done)/Time

Where work (w) = 500,000J and time (t) is 50 min.

1 min = 60 sec

50 min = 50 × 60 = 3000 sec

Substitute the values,

→ P = 500,000J/3000s

→ P = 500J/3s

→ P = 166.66 J/s

→ P = 166.66 watt

Hence, the power is 166.66 W.