• Understand how the following effect motion of a projectile:
  • Launch angle
  • Launch velocity
  • Free fall acceleration
• Use vectors to describe the motion of a block on a ramp and the forces acting upon it
• Apply Newton's 2nd Law to relate the acceleration of a block on a ramp to the forces acting on it

• 2-Dimensional kinematics
  • Projectile motion
• Newton's 2nd Law
• Drag

• Interpretation of preexisting code
• Changing values of given code

Part 1
Copy and paste the code from this GlowScript program. Click the button to launch the ball. Your goal is to hit the target.

1. What 3 variables can you change that might enable the ball to hit the target? Ignore drag for right now.
   1. Variable 1:
   2. Variable 2:
   3. Variable 3:
2. Now edit these variables and run the program until the ball successfully hits the target. Repeat twice more with different combinations of variables. Record your trials below:

Part 2 Answer the following questions that are related to the program and projectile motion.

1. What do the green arrows represent? How do they change over time?
2. What do the blue arrows represent? How do they change over time?
3. How does changing the mass of the ball affect the motion of the ball and the size of the arrows?

Part 3 Extra: Within the code you’ll find a reference to the drag coefficient (line 27). Change the value to something between 0.01 and 0.001. Click to “Run this program”.

1. Describe how the motion is different now that drag is incorporated into the program
2. How are the blue arrows different from the trials without drag?
3. Now, with drag included, modify the variables until the ball hits the target again, and record your results in the table below:

Link

GlowScript 2.7 VPython
get_library('https://rawgit.com/perlatmsu/physutil/master/js/physutil.js')
 
#objects
x = 0
y = 0
ball = sphere(pos=vector(x,y,0), radius=10, color=vector(1,0,0), texture=textures.rough, make_trail=True)
ballmass = 10
 
platform = box(pos=vector(0,-25,0), length=100, height=50, width=1, color=color.orange)
pL = label(pos=vector(0,200,0), text='Click to Launch', space=30, height=16, border=4, font='sans')
 
target = box(pos=vector(800,-25,0), length=100, height=50, width=1, color=vector(0.8,0.8,0))
tL = label(pos=vector(800,-75,0), text='Target', space=30, height=16, border=4, font='sans')
 
 
 
#Window setup
scene.range = 480
scene.center = vector(400,100,0)
scene.width = 960
scene.height = 600
scene.background = vector(0.5,0.5,0.5)
 
#Parameters and Initial Conditions
g = vector(0,-8,0) #Free Fall acceleration
b = 0.000  #Drag coefficient
 
 
#Time and time step
t = 0
tf = 10
dt = 0.01
 
#velocity
v0 = 60
theta = 55
vx = v0*cos(theta*pi/180)
vy = v0*sin(theta*pi/180)
ballv = vector(vx,vy,0)
 
#motion map
motionmapv = MotionMap(ball, tf, 5, markerScale=.8, markerColor=color.green, labelMarkerOrder=False)
motionmapa = MotionMap(ball, tf, 5, markerScale=6, markerColor=color.blue, labelMarkerOrder=False)
 
#graph
gd = graph(width=600, height=250, title='<b>Horizontal Range vs. Time</b>', 
    xtitle='<i>time</i>', ytitle='<i>Horizontal Range</i>', 
    foreground=color.black, background=color.white, 
    xmin=0, xmax=15, ymin=0, ymax=1000)
rangecurve = gcurve(color=color.red)
 
gd = graph(width=600, height=250, title='<b>Height vs. Time</b>', 
    xtitle='<i>time</i>', ytitle='<i>Height</i>', 
    foreground=color.black, background=color.white, 
    xmin=0, xmax=15, ymin=0, ymax=1000)
heightcurve = gcurve(color=color.green)
 
ev = scene.waitfor('click')
 
while ball.pos.y >= 0:
    rate(500)
 
    Fgrav = ballmass*g
    Fdrag = -b*ballv*mag(ballv)
    Fnet = Fgrav + Fdrag
 
    balla = Fnet/ballmass
 
    ball.pos = ball.pos + ballv*dt
    ballv = ballv + balla*dt
 
    motionmapv.update(t, ballv)
    motionmapa.update(t, balla)
 
    #rangecurve.plot(t,ball.pos.x)
    #heightcurve.plot(t,ball.pos.y)
 
    t = t + dt