• VPhysics程式設計

動量

• 講義

• 比較有相同動量但不同質量的物體速度的快慢

  Web VPython 3.2
  # 匯入視覺化套件
  from vpython import *
  
  #  1. 參數設定
  #物質密度 單位: kg/m**3
  density_stucco = 400.0
  density_metal = 900.0
  density_earth = 2600.0
  #球半徑 0.05m
  size = 0.05
  #地板長
  L = 1.00
  #時間間隔
  dt = 0.001
  #體積
  V = (4/3)*pi*(size)**3
  #初始動量 kg*m/s
  P = 0.1
  
  #  2. 畫面設定
  scene = canvas(width=800, height=800, background=vector(0.5,0.6,0.5))
  bottom = box(pos=vector(0,-size,0), length=2*L, height=0.001, width=2)
  wall = box(pos=vector(L,-size/2,0), length=0.01, height=size, width=2)
  
  #  3. 球的設定
  ball_stucco = sphere(pos=vector(-L,0,-0.40), radius=size, texture=textures.stucco)
  ball_metal = sphere(pos=vector(-L,0,0), radius=size, texture=textures.metal)
  ball_earth = sphere(pos=vector(-L,0,0.40), radius=size, texture=textures.earth)
  
  #質量
  ball_stucco.m = V*density_stucco
  ball_metal.m = V*density_metal
  ball_earth.m = V*density_earth
  #速度
  ball_stucco.v = P / ball_stucco.m
  ball_metal.v = P / ball_metal.m
  ball_earth.v = P / ball_earth.m
  
  #  4. 運動
  while True:
      rate(1000)
      ball_stucco.pos.x = ball_stucco.pos.x + ball_stucco.v * dt
      ball_stucco.rotate(axis=vector(0,0,1), angle = -ball_stucco.v*dt/size)
      if ball_stucco.pos.x >= L-size:
          ball_stucco.v = 0
  
      ball_metal.pos.x = ball_metal.pos.x + ball_metal.v * dt
      ball_metal.rotate(axis=vector(0,0,1), angle = -ball_metal.v*dt/size)
      if ball_metal.pos.x >= L-size:
          ball_metal.v = 0
  
      ball_earth.pos.x = ball_earth.pos.x + ball_earth.v * dt
      ball_earth.rotate(axis=vector(0,0,1), angle = -ball_earth.v*dt/size)
      if ball_earth.pos.x >= L-size:
          ball_earth.v = 0

  【作業】

  請修改上述程式碼，使用串列(list)與迴圈(for loop)畫出三顆滾動的球。