What type of exercise is the most appropriate in cool down as they help the muscles to relax

Stretching as part of your cool-down

Stretching helps to relax your muscles and restore them to their resting length, and improve flexibility (the range of movement about your joints). As a guide, allow 10 minutes of post-exercise stretching for every one hour of exercise.

Static Stretching

This is a very effective way to increase flexibility. Static stretches should be used as part of your cool-down routine to help prevent injury. Using static stretching as a maintenance stretching program will also help reduce your risk of injury

the gravitational force on an object increase as the mass of an object also, im not going to report you, but this question should be under the science category, not health