A vehicle needs an engine of 7500 W to keep it moving with a constant velocity of 20 `ms^(-1)` on a horizontal surface. The force resisting the motion is

Options

A. 375 dyne
B. 375 N
C. 150000 dyne
D. 150000 N

Explanation

To solve the problem, we need to find the force resisting the motion of the vehicle. We are given the power required to keep the vehicle moving and its velocity.

### Step-by-Step Solution:

1. **Identify the Given Values:**
- Power (P) = 7500 W
- Velocity (v) = 20 m/s

2. **Use the Power Formula:**
The relationship between power, force, and velocity is given by the formula:
\[ P = F \cdot v \]
where \( P \) is power, \( F \) is force, and \( v \) is velocity.

3. **Rearrange the Formula to Solve for Force:**
To find the force, we can rearrange the formula:
\[ F = \frac{P}{v} \]

4. **Substitute the Known Values:**
Now, substitute the values of power and velocity into the equation:
\[ F = \frac{7500 \, \text{W}}{20 \, \text{m/s}} \]

5. **Calculate the Force:**
Performing the division:
\[ F = \frac{7500}{20} = 375 \, \text{N} \]

6. **Conclusion:**
The force resisting the motion of the vehicle is 375 N.

### Final Answer:
The force resisting the motion is **375 N**.

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