What is the formula to calculate the force required to lift a granite slab with a wedge?

The formula to calculate the force required to lift a granite slab with a wedge is based on the principles of mechanics and the use of angles in relation to the weight of the object being lifted. When using a wedge, the force exerted is influenced by the angle of the wedge.

In this case, the correct choice involves multiplying the weight of the slab by the sine of the angle. This relationship can be understood through the concept of resolving forces. When a force is applied at an angle, it can be decomposed into two components: one that acts vertically and another that acts horizontally. The vertical component is responsible for lifting the weight directly upward.

Using the sine function reflects the vertical aspect of the force relative to the angle of the wedge. Essentially, the sine of the angle gives the ratio of the opposite side (height) to the hypotenuse in a right triangle. Therefore, the formula correctly reflects how a smaller input force at a specific angle can still effectively lift a heavier weight due to the mechanical advantage provided by the inclined plane that the wedge creates.

Other options do not correctly represent this relationship. Multiplying by the angle or using cosine does not appropriately capture the mechanics of lifting in this context.