chunkin_punkin.py

import math
import sys
from typing import Optional


class LaunchConfig:
    def __init__(
        self,
        theta: float,
        total_length: float,
        initial_height: float,
        final_height: float,
    ) -> None:
        self.theta_degrees = theta
        self.theta = math.radians(theta)
        self.total_length = total_length
        self.initial_height = initial_height
        self.final_height = final_height

    def __str__(self) -> str:
        msg = f"""LaunchConfig(
    theta={self.theta_degrees},
    total_length={self.total_length},
    initial_height={self.initial_height},
    final_height={self.final_height}
    )"""
        return msg


class ChunkinPunkin:
    G = 9.81  # m/s^2
    CONVERSION = 3.6

    def _get_alpha(self, config: LaunchConfig) -> float:
        alpha = (
            math.tan(config.theta) * config.total_length
            + config.initial_height
            - config.final_height
        )
        return alpha

    def _get_numerator(self, config: LaunchConfig) -> float:
        return config.total_length**2 * self.G

    def _get_denominator(self, config: LaunchConfig) -> float:
        return 2 * math.cos(config.theta) ** 2 * self._get_alpha(config)

    def get_needed_speed(self, config: LaunchConfig) -> float:
        v_square = self._get_numerator(config) / self._get_denominator(config)
        v = math.sqrt(v_square)
        return v

    def get_flight_time(
        self, config: LaunchConfig, launch_speed: Optional[float] = None
    ) -> float:
        if launch_speed is None:
            launch_speed = self.get_needed_speed(config)
        t = config.total_length / (launch_speed * math.cos(config.theta))
        return t

    @classmethod
    def to_kmh(cls, speed: float) -> float:
        converted_speed = cls.CONVERSION * speed
        return converted_speed

    def report(self, config: LaunchConfig) -> None:
        speed = self.get_needed_speed(config)
        speed_kmh = self.to_kmh(speed)
        flight_time = self.get_flight_time(config, speed)
        print(config)
        print("Launch speed =", round(speed, 2), "m/s", round(speed_kmh, 2), "km/h")
        print("Flight time =", round(flight_time, 2), "s")


if __name__ == "__main__":
    args = sys.argv
    (length, initial_height, final_height) = (
        float(args[1]),
        float(args[2]),
        float(args[3]),
    )
    print("Arguments: ", args[1:])
    thetas = [15.0, 30.0, 45.0, 60.0, 75.0, 80.0, 85.0, 90.0]
    calculator = ChunkinPunkin()
    for theta in thetas:
        config = LaunchConfig(theta, length, initial_height, final_height)
        calculator.report(config)