Final answer:
The mechanical advantage of an inclined plane with a length of 15 and a height of 5 is found by dividing the length by the height, which results in a mechanical advantage of 3.
Step-by-step explanation:
To find the mechanical advantage (MA) of an inclined plane, you divide the length of the incline (also known as the hypotenuse) by the height. Given that the length of the incline is 15 and the height is 5, we can calculate the mechanical advantage using the formula MA = Length / Height.
MA = 15 / 5
MA = 3
Therefore, the mechanical advantage of the inclined plane is 3. This means that the force required to move an object up the incline would be one-third of the force required to lift it vertically. The correct answer to the question is option (d) 3.