To find the work done by Mark on Sarah, we use the formula for work done when a force is applied at an angle:

$W = F \cdot d \cdot \cos(\theta)$

where:

• $F = 30 \, \text{N}$ is the force applied,
• $d = 25 \, \text{m}$ is the distance over which the force is applied,
• $\theta = 15^\circ$ is the angle between the force and the horizontal direction.

Step-by-Step Calculation

1. Calculate $\cos(15^\circ)$: $\cos(15^\circ) \approx 0.9659$

2. Substitute values into the work formula: $W = 30 \cdot 25 \cdot 0.9659$

3. Perform the multiplication: $W \approx 724.425 \, \text{J}$

Rounding to the nearest tenth, we get: $W \approx 724.4 \, \text{J}$

Answer

The closest answer is: D. 724.7 J

Would you like more details or have any questions?

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1. What is the significance of the angle in calculating work?
2. How does the force direction affect work done if the angle were 90°?
3. Why is work measured in joules?
4. How would friction affect the work calculation?
5. How do we calculate work if the force is not constant?

Tip: When calculating work with an angle, always use the horizontal component of the force for accurate results.