import math


def chute_size(mass, velocity=3, drag=0.75, gravity=9.8, air_density=1.22):
    """
        Determine the required size of a chute given a mass and a velocity.
            mass: mass of rocket in kg
            velocity: velocity of the rocket when it hits the earth in m/s
            drag: drag coefficient for chute
    """
    return math.sqrt((8 * mass * gravity) / (math.pi * air_density * drag * velocity ** 2))