A boy on a swing set has a speed of 4.5 m/s and a centripetal acceleration of 8.1 m/s2 at the bottom of his swing. How long are the ropes of the swing? Pls help

R = 1.8 m

Explanation:

This is a simple harmonic movement exercise, at the bottom of the swing the acceleration is vertical upwards and the speed is tangential to the trajectory, that is horizontal; the expression for the centralized acceleration is

              = v² / R

              R = v² /a_{c}

where the radius is equal to the length of the swing

let's calculate

            R = 8.1 / 4.5

            R = 1.8 m

the answer you are looking for is d. there are no holes for blood to enter or leave the system. your welcome