Question

We all know it makes sense to bend one's knees when dropping from a height. Suppose a very silly 70-kg person were instead to drop down from a height of 1.4 m onto the ground and stop stiffly within a distance of only 0.60 cm. Calculate how many times his own weight is the average force his body feels.

Answer 1

When a person jumps from a height and lands stiffly without bending their knees, the force experienced by their body can be calculated using the change in gravitational potential energy. The force can be divided by the person's weight to find how many times his own weight is the average force his body feels.

Step-by-step explanation:

When a person jumps from a height and lands stiffly without bending their knees, the force experienced by their body can be calculated. Let's consider the example of a 70 kg person dropping from a height of 1.4 m and stopping within a distance of 0.60 cm.

First, we need to calculate the change in gravitational potential energy (ΔPE) of the person. This can be calculated using the formula ΔPE = mgh, where m is the mass, g is the gravitational acceleration (9.8 m/s^2), and h is the height.

Next, we calculate the average force (F) experienced by the person using the formula F = ΔPE / d, where d is the stopping distance.

Once we have the value of the force, we can divide it by the weight of the person to find how many times his own weight is the average force his body feels.