Unit 3 Lesson 1 Kinematics in 2D Simulations

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Physics

Unit 3 Lesson 1


Kinematics in 2D


Simulations

Student Name: ___________________________

Class: __________________________________


Date: ___________ Period: _________________


Moving Man


Simulation


Using the Moving Man Simulation, investigate how the controls work and answer the questions below. The
simulation is located at
http://phet.colorado.edu/new/index.php
. In this simulation, the distance traveled
is given the symbol x. This and d are both com
monly used for 1D motion.


1. Where is the time displayed? _______________________________


2. The three motion graphs displayed are x
-
t, _______ and _________.


3. The man has a habit of running into the wall. How do you remove the wall? __________


4
. Change the magnitude of the velocity in the velocity box to 1m/s. Press play to allow the moving man to
move for approximately two seconds before pressing stop. His motions have been recorded. Now click on the
playback button and then click play. A thin
gray vertical bar leads the graphing line. This bar marks the time for
the values in the boxes at the left. What happens when you grab the bar and move it? ____________


The values for x, v, and a, are shown in the box on the left. Only two significant fi
gures are displayed for the
time, while the boxes display three digits for x, v, and a.


5. Remove the wall. Set a = 0, v = 0.5, and x = 0 at the start (initial conditions) and run (record) the simulation
for approximately 3 seconds. From the simulation,
select playback to play the recording.




By moving the vertical bar, can you set the time at 1.0 s? _______ (yes/no)




What is the v value in the box at exactly 1.1 s? _______ m/s: What is the calculated velocity from the
d/t data? _____m/s




Carefully dra
g the vertical bar so that the time remains the same, but the displacement changes. What
is the v value in the box at 1.1 s? ______ m/s: What is the calculated velocity from the d/t data? _____
m/s




What is the x value in the box at t = 0 sec? ______ m: W
hat is the calculated displacement from the
data? _____m




What value do you calculate for the v value at a displacement of 1.0 m? ________ m/s





Some programs do not use the exact equations to simulate motion, but rely on approximate methods which
may be easier to program and may intentionally introduce “error fluctuations” to the results. The values in
the boxes are accurate to three significant f
igures.


6. Set a = 0.5, v = 0, x = 0 and run the simulation for 2 seconds. Examine the values at a position of 1.13 m.




What is the measured time? ________s




What is the velocity value in the box? ________m/s




What is the acceleration value in the box
? ________m/s2




Using your kinematic equations and the data provided in the boxes, calculate the acceleration.





Does the calculated acceleration agree with the data in the acceleration box? _______



7. Set a = 0.5, v = 0.5, x = 0 and run the simulatio
n for 2 seconds. Examine the values at a position of 1.53 m.




What is the measured time? ________s




What is the velocity value in the box? ________m/s




What is the acceleration value in the box? ________m/s2




Using your kinematic equations and the data

provided in the boxes, calculate the acceleration.




Does the calculated acceleration agree with the data in the acceleration box?



8. From your experience with this simulation, what has given you more accurate results, the calculated data or
the data provided in the boxes by the simulation?



Physics

Unit 3 Lesson 1


Kinematics in 2D


Simulations

Student Name: ____________________
_______

Class: __________________________________


Date: ___________ Period: _________________

“Projectile Motion” Simulation


Investigate the controls and answer the questions for the Projectile Motion Simulation. The simulation is
located at
http://www.walter
-
Fendt.de/ph14e/projectile.htm
. In this simulation, the horizontal distance
traveled is given the symbol
x
and the vertical motion coordinate is
y
.


1. Where is the total time of flight displayed? _____________________

2. Can you slow do
wn the motion? _____________________

3. Can you move the simulation backward and forward? _____ (yes/no)

4. Positive values of
x
are to the right of the
y
-
axis; positive values of
y
are ______ (up or down).

5. The values in the boxes to the right of the

screen in the green field are ______. (initial or final values)

6. How can the initial values for
x
,
v
, and
a
be set? _______________________

7. Range is the distance traveled in the
x
direction upon impact with the ground. How do you find that value?
_
______________________

8. Where is the time found in the display? ___________________________

9. Click the acceleration button to determine the direction of the acceleration. Acceleration is ______ (up or
down). Thus, the display should really give a neg
ative value. It does not.

10. Click the velocity button.
vx
and
vy
are the speeds in the
x
and
y
directions. (These are called components
of the velocity). Which component changes as the motion proceeds? ______ (
x
or
y
)

11. What is the time for a project
ile to hit the ground if shot horizontally from a height of 100 m at a speed of
20 m/s? ________ s

12. What is the time for a projectile to hit the ground if shot horizontally from a height of 100 m at a speed of
40m/s? ________ s

13. Use the equation
x
= vxt
to calculate the distance for a projectile shot horizontally at a speed of 60 m/s
from a height of 100 m. ____________. Does this work? ____ (yes/no)

14. Shoot a projectile straight up from ground
-
level. Compare the time going up to the time coming
down.
What did you find? _________________. Does this work for different initial speeds? ____

15. Shoot a projectile straight up from ground
-
level. Compare the speed at which it is shot to the speed at
which it hits the ground. What did you find? ________
_____________

16. For the same speed and angle, does the range increase if shot from a higher tower? ____

17. For the same initial conditions, does the range depend upon the angle of the shot? _____

You will find that working with projectile motion
using the components of motion (
x
and
y
) is easier than
working with the speed and angle of the motion. Notice that the velocity button provides both the velocity
components and also the speed and angle of the motion. Velocity is a vector which has both ma
gnitude
(speed) and direction.