Question

Quiz
Question 1 (3 points)

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P = 25 watts

W = 5000 Joules

t =?

Question 1 options:

200 seconds


0.005 seconds


125,000 J


200 watts

Question 2 (3 points)

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How much time is needed to produce 720 Joules of work if 90 watts of power is used?



Question 2 options:

64,800 watts


8 watts


0.125 seconds


8 seconds

Question 3 (3 points)

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If a man moves a large box that weighs 10 Newtons 20 meters in 30 seconds, how much power was used?



Question 3 options:

300 watts


600 J


6.67 watts


300 seconds

Question 4 (3 points)

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P = 170 watts

t = 20 seconds

W =?



Question 4 options:

0.12 J


3,400 J


3,400 seconds


8.5 watts

Question 5 (3 points)

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W= 500 Joules

t = 25 seconds

P =?



Question 5 options:

12,500 watts


12,500 J


20 J


20 watts


0 of 5 questions saved
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Answer 1

Let's break down each question using the relevant formulas.

### Question 1
Given:
- Power (P) = 25 watts
- Work (W) = 5000 Joules
- Time (t) = ?

To find t, we use the formula:
\[
P = \frac{W}{t}
\]
Rearranging gives us:
\[
t = \frac{W}{P}
\]
Substituting the values:
\[
t = \frac{5000 \text{ J}}{25 \text{ W}} = 200 \text{ seconds}
\]

**Answer: 200 seconds**

---

### Question 2
Given:
- Work (W) = 720 Joules
- Power (P) = 90 watts

Using the same formula:
\[
t = \frac{W}{P}
\]
Substituting the values:
\[
t = \frac{720 \text{ J}}{90 \text{ W}} = 8 \text{ seconds}
\]

**Answer: 8 seconds**

---

### Question 3
Given:
- Weight of the box (Force, F) = 10 Newtons
- Distance (d) = 20 meters
- Time (t) = 30 seconds

First, calculate work using:
\[
W = F \cdot d = 10 \text{ N} \cdot 20 \text{ m} = 200 \text{ Joules}
\]
Now, use power formula:
\[
P = \frac{W}{t}
\]
Substituting the values:
\[
P = \frac{200 \text{ J}}{30 \text{ s}} \approx 6.67 \text{ watts}
\]

**Answer: 6.67 watts**

---

### Question 4
Given:
- Power (P) = 170 watts
- Time (t) = 20 seconds

Using the power formula again:
\[
W = P \cdot t
\]
Substituting the values:
\[
W = 170 \text{ W} \cdot 20 \text{ s} = 3400 \text{ Joules}
\]

**Answer: 3,400 J**

---

### Question 5
Given:
- Work (W) = 500 Joules
- Time (t) = 25 seconds

Power calculation:
\[
P = \frac{W}{t}
\]
Substituting the values:
\[
P = \frac{500 \text{ J}}{25 \text{ s}} = 20 \text{ watts}
\]

**Answer: 20 watts**

---

### Summary of Answers:
1. 200 seconds
2. 8 seconds
3. 6.67 watts
4. 3,400 J
5. 20 watts