Who you be? ___________________
Welcome to the study of PROJECTILE MOTION (Chapter 6). This chapter will rely heavily on your knowledge of A) the
“fab four” equations (kinematics) and B) vectors. This activity is meant to introduce you to many of the most important
concepts of projectile motion.
Directions: Go to the following website:
http://www.walter-fendt.de/ph11e/projectile.htm
This will bring up a java applet that will simulate projectile
launches. You can change:
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Initial height of the projectile
Initial speed of the projectile
The angle of inclination of the projectile
The mass of the projectile
The acceleration of gravity that acts on the projectile
or just “Google” search “projectile motion fendt”
SIMULATIONS 1-8 HORIZONTALLY LAUNCHED VS. DROPPED PROECTILE FROM THE SAME HEIGHT
Simulation 1 – Horizontally Launched Projectile
Simulation 2 – Dropped Projectile
Initial height = 20m
Initial speed = 30m/s
Angle = 0o
Mass = 1kg
Gravitational acceleration = 9.81 m/s2
Initial height = 20m
Initial speed = 0m/s
Angle = 0o
Mass = 1kg
Gravitational acceleration = 9.81 m/s2
Total Time of Flight? _______
Total Time of Flight? _______
How do the times of flight for Simulations 1 & 2 compare?
Is this strange to you?
Maybe it was just dumb luck that they had the same time (launched and dropped) Try it again with different values!
Simulation 3 – Horizontally Launched Projectile
Simulation 4 – Dropped Projectile
Initial height = 100m
Initial speed = 50m/s
Angle = 0o
Mass = 1kg
Gravitational acceleration = 9.81 m/s2
Initial height = 100m
Initial speed = 0m/s
Angle = 0o
Mass = 1kg
Gravitational acceleration = 9.81 m/s2
Total Time of Flight? _______
Total Time of Flight? _______
How do the times of flight for Simulations 3 & 4 compare?
What do you think will happen if you keep the same heights (launched and dropped) but launch the ball at an angle
greater than the horizontal? PREDICT BEFORE YOU RUN THE SIMULATION!!!
Simulation 5 – Non-Horizontally Launched Projectile
Simulation 6 – Dropped Projectile
Initial height = 75m
Initial speed = 50m/s
Angle = 30o
Mass = 1kg
Gravitational acceleration = 9.81 m/s2
Initial height = 75m
Initial speed = 0m/s
Angle = 0o
Mass = 1kg
Gravitational acceleration = 9.81 m/s2
Total Time of Flight? _______
Total Time of Flight? _______
How do you explain the fact that the launched ball now spends more time in the air than the dropped ball?
What do you think will happen if you keep the same heights (launched and dropped) but launch the ball at an angle less
than the horizontal? PREDICT BEFORE YOU RUN THE SIMULATION!!!
Simulation 7 – Non-Horizontally Launched Projectile
Simulation 8 – Dropped Projectile
Initial height = 80m
Initial speed = 100m/s
Angle = -30o (notice that the angle is negative!)
Mass = 1kg
Gravitational acceleration = 9.81 m/s2
Initial height = 80m
Initial speed = 100m/s
Angle = 0o
Mass = 1kg
Gravitational acceleration = 9.81 m/s2
Total Time of Flight? _______
Total Time of Flight? _______
How do you explain the fact that the launched ball now spends less time in the air than the dropped ball?
Simulations 9-11 HORIZONTALLY LAUNCHED PROJECTILES WITH DIFFERENT INITIAL SPEEDS
What do you think will happen if you launch three projectiles from the same height, but at different speeds?
PREDICT BEFORE YOU RUN THE SIMULATION!!!
Simulation 9 – Horizontally Launched
Projectile
Simulation 10 – Horizontally
Launched Projectile
Simulation 11 - Horizontally
Launched Projectile
Initial height = 100m
Initial speed = 50m/s
Angle = 0o
Mass = 1kg
Gravitational acceleration = 9.81 m/s2
Initial height = 100m
Initial speed = 75m/s
Angle = 0o
Mass = 1kg
Gravitational acceleration = 9.81 m/s2
Initial height = 100m
Initial speed = 100m/s
Angle = 0o
Mass = 1kg
Gravitational acceleration = 9.81 m/s2
Total Time of Flight? _______
Total Horizontal Distance? ______
Total Time of Flight? _______
Total Horizontal Distance? ______
Total Time of Flight? _______
Total Horizontal Distance? ______
So according to Simulations 9, 10, & 11 (previous page) the time of flight for a horizontally launched projectile is ONLY
DEPENDENT UPON __________________________________.
This is a very important concept!
So, if the time of flight of a horizontally launched projectile is only dependent upon the initial height of the object, let’s
see if you can calculate the horizontal range of the following projectiles.
Do the following to show that you understand horizontally launched projectiles:
A) Given the height of the horizontal projectile launch, use a fab four equation to calculate the time to drop (it’s
the same as if it were just dropped from rest – vi = 0).
B) Take that time and use it to find the horizontal range (Distance = Velocity x Time).
C) Use the simulation to check your answer.
A
INITIAL CONDITIONS
Initial height = 78.5m
Initial speed = 10m/s
Angle = 0o
Mass = 1kg
g= 9.81 m/s2
CALCULATION OF TIME TO FALL
CALCULATION OF HORIZONTAL RANGE
Simulation Result ___________
B
INITIAL CONDITIONS
Initial height = 44.15m
Initial speed = 35m/s
Angle = 0o
Mass = 1kg
g= 9.81 m/s2
CALCULATION OF TIME TO FALL
CALCULATION OF HORIZONTAL RANGE
Simulation Result ___________
C
INITIAL CONDITIONS
Initial height = 55.5m
Initial speed = 60m/s
Angle = 0o
Mass = 1kg
g= 9.81 m/s2
CALCULATION OF TIME TO FALL
CALCULATION OF HORIZONTAL RANGE
Simulation Result ___________
CAN YOU WORK BACKWARDS? FILL IN THE BLANKS!
D
INITIAL CONDITIONS
Initial height = 78.5m
Initial speed = ? ? ?
Angle = 0o
Mass = 1kg
g= 9.81 m/s2
CALCULATION OF TIME TO FALL
CALCULATION OF HORIZONTAL RANGE
60 meters
Simulation Result ___________
E
INITIAL CONDITIONS
Initial height = 20m
Initial speed = ???
Angle = 0o
Mass = 1kg
g= 9.81 m/s2
CALCULATION OF TIME TO FALL
CALCULATION OF HORIZONTAL RANGE
90 meters
Simulation Result ___________
F
INITIAL CONDITIONS
Initial height = ? ? ?
Initial speed = 25 m/s
Angle = 0o
Mass = 1kg
g= 9.81 m/s2
CALCULATION OF TIME TO FALL
CALCULATION OF HORIZONTAL RANGE
25m
Simulation Result ___________
G
INITIAL CONDITIONS
Initial height = ???
Initial speed = 22.2 m/s
Angle = 0o
Mass = 1kg
g= 9.81 m/s2
CALCULATION OF TIME TO FALL
CALCULATION OF HORIZONTAL RANGE
36.8
Simulation Result ___________