"""Tests for circular motion calculations."""
import math
from chuk_mcp_physics.circular_motion import (
CentripetalForceRequest,
OrbitalPeriodRequest,
BankingAngleRequest,
EscapeVelocityRequest,
CircularOrbitRequest,
calculate_centripetal_force,
calculate_orbital_period,
calculate_banking_angle,
calculate_escape_velocity,
analyze_circular_orbit,
)
class TestCentripetalForce:
def test_car_turning(self):
"""Test centripetal force for a car turning."""
request = CentripetalForceRequest(
mass=1500.0,
velocity=20.0,
radius=50.0,
)
result = calculate_centripetal_force(request)
# F_c = m * v² / r
expected = 1500.0 * 20.0 * 20.0 / 50.0
assert abs(result.centripetal_force - expected) < 1.0
assert abs(result.centripetal_acceleration - (20.0 * 20.0 / 50.0)) < 0.1
class TestOrbitalPeriod:
def test_iss_orbit(self):
"""Test orbital period for ISS."""
request = OrbitalPeriodRequest(
orbital_radius=6.771e6, # meters
central_mass=5.972e24, # Earth mass
)
result = calculate_orbital_period(request)
# Period should be around 90-95 minutes
assert 5000 < result.period < 6000 # seconds
period_minutes = result.period / 60.0
assert 80 < period_minutes < 100
class TestBankingAngle:
def test_highway_ramp(self):
"""Test banking angle for highway ramp."""
request = BankingAngleRequest(
velocity=25.0,
radius=100.0,
gravity=9.81,
)
result = calculate_banking_angle(request)
# θ = arctan(v² / (rg))
expected = math.atan((25.0 * 25.0) / (100.0 * 9.81))
assert abs(result.angle_radians - expected) < 0.01
assert abs(result.angle_degrees - math.degrees(expected)) < 0.1
class TestEscapeVelocity:
def test_earth_escape(self):
"""Test escape velocity from Earth."""
request = EscapeVelocityRequest(
mass=5.972e24, # Earth mass
radius=6.371e6, # Earth radius
)
result = calculate_escape_velocity(request)
# Should be around 11,200 m/s
assert 11000 < result.escape_velocity < 11500
assert 39600 < result.escape_velocity_kmh < 41400
class TestCircularOrbit:
def test_leo_satellite(self):
"""Test circular orbit analysis for LEO satellite."""
request = CircularOrbitRequest(
altitude=400000.0, # 400 km
planet_mass=5.972e24, # Earth
planet_radius=6.371e6, # Earth
)
result = analyze_circular_orbit(request)
# Orbital radius should be planet radius + altitude
expected_radius = 6.371e6 + 400000.0
assert abs(result.orbital_radius - expected_radius) < 1000
# Orbital velocity should be around 7,670 m/s
assert 7500 < result.orbital_velocity < 7800
# Period should be around 90-95 minutes
assert 5000 < result.period_seconds < 6000
# Centripetal acceleration should be positive
assert result.centripetal_acceleration > 0
