curriculum/challenges/english/blocks/learn-encapsulation-by-building-a-projectile-trajectory-calculator/662f9f65c50bd21d05ffdee9.md
Define a method named calculate_all_coordinates, which calculates the coordinates for all \(x\) values from 0 up to the displacement rounded up (not inclusive), and then returns them as a list of tuples (x, y).
Then, call the calculate_all_coordinates method on the ball instance and assign the output to a new variable named coordinates.
You can use math.ceil() to round up a number to the smallest integer greater than or equal to that number.
You should define a calculate_all_coordinates method with a single argument, self .
({test: () => assert(runPython(`
c = _Node(_code).find_class('Projectile')
c.has_function('calculate_all_coordinates') and c.find_function('calculate_all_coordinates').has_args('self')
`))})
You should call the calculate_all_coordinates method on ball and assign the result to a variable named coordinates.
({
test: () => runPython(`
assert _Node(_code).has_variable('coordinates'), "coordinates variable is missing"
assert _Node(_code).find_variable('coordinates').is_equivalent('coordinates = ball.calculate_all_coordinates()'), "wrong value assigned to coordinates variable"
`)
})
The calculate_all_coordinates method should return a list containing all the (x, y) coordinates.
({test: () => assert(runPython(`
import math
GRAVITATIONAL_ACCELERATION = 9.81
PROJECTILE = "∙"
x_axis_tick = "T"
y_axis_tick = "⊣"
ball = Projectile(12, 13, 14)
expected = [(x, ball._Projectile__calculate_y_coordinate(x)) for x in range(math.ceil(ball._Projectile__calculate_displacement()))]
actual = ball.calculate_all_coordinates()
expected == actual
`))})
import math
GRAVITATIONAL_ACCELERATION = 9.81
PROJECTILE = "∙"
x_axis_tick = "T"
y_axis_tick = "⊣"
class Projectile:
__slots__ = ('__speed', '__height', '__angle')
def __init__(self, speed, height, angle):
self.__speed = speed
self.__height = height
self.__angle = math.radians(angle)
def __str__(self):
return f'''
Projectile details:
speed: {self.__speed} m/s
height: {self.__height} m
angle: {round(math.degrees(self.__angle))}°
displacement: {round(self.__calculate_displacement(), 1)} m
'''
def __calculate_displacement(self):
horizontal_component = self.__speed * math.cos(self.__angle)
vertical_component = self.__speed * math.sin(self.__angle)
squared_component = vertical_component**2
gh_component = 2 * GRAVITATIONAL_ACCELERATION * self.__height
sqrt_component = math.sqrt(squared_component + gh_component)
return horizontal_component * (vertical_component + sqrt_component) / GRAVITATIONAL_ACCELERATION
def __calculate_y_coordinate(self, x):
height_component = self.__height
angle_component = math.tan(self.__angle) * x
acceleration_component = GRAVITATIONAL_ACCELERATION * x**2 / (
2 * self.__speed**2 * math.cos(self.__angle)**2)
y_coordinate = height_component + angle_component - acceleration_component
return y_coordinate
--fcc-editable-region--
ball = Projectile(10, 3, 45)
print(ball)
--fcc-editable-region--