By applying a force of 50 N, a pulley system can lift a box with a mass of 20 kg.  What is the mechanical advantage of the pulley system?

To find the mechanical advantage of the pulley system, we need to first understand what mechanical advantage is. Mechanical advantage is the ratio of the output force to the input force in a machine.

In this case, the input force is the force applied to the pulley system, which is 50 N. The output force is the force required to lift the box, which is the weight of the box.

The weight of an object can be calculated using the formula: weight = mass x gravity, where gravity is approximately 9.8 m/s^2.

So, the weight of the box is: weight = 20 kg x 9.8 m/s^2 = 196 N.

Now, we can calculate the mechanical advantage using the formula: mechanical advantage = output force / input force.

In this case, the output force is the weight of the box, which is 196 N, and the input force is 50 N.

Therefore, the mechanical advantage of the pulley system is: mechanical advantage = 196 N / 50 N = 3.92.

So, the mechanical advantage of the pulley system is approximately 3.92.