ROCKET SLED Name
PS Unit 2: Newton’s Law & Forces Date Hour
**Please write all answers in a different color. Otherwise, points will be deducted from your assignment.
BEFORE YOU BEGIN:
You will write on a PDF to complete this activity. Before you get started, you must learn how to write on a PDF by watching the
video or reading the tutorial posted on Canvas.
Q1: Be aware of the 5 Forces and their abbreviations that we will be using for this activity. What does it stand for?
FN Fapp
Ff Fair
Fg
*YOU SHOULD MEMORIZE THESE ASAP!
GETTING STARTED:
1. Click Physics Simulation: Balanced and Unbalanced Forces to go to the simulation.
2. Click “Launch Interactive” to start the interactive. Note: You can resize the interactive to make it larger.
3. Take a few minutes playing with the Rocket Sled to see how it works. Then, continue to the next part, Explore.
Q2: You can’t get rid of the arrows pointing VERTICALLY (up & down). Which forces are these representing?
UP ARROW: . DOWN ARROW: .
Q3: There is a way to make the VERTICAL arrows longer. What do you have to do? .
EXPLORE: Follow the directions in each question to set up the Rocket Sled. Read each question carefully to make sure you
answer all parts. Then, double click the diagram to use the GOOGLE DRAW tool and be sure to include TEXT to label the force
diagram. Before we begin, know what each abbreviation stands for in Q1 above!
1. With Friction and Air Drag turned off, slide the blue switch to the right
slightly.
a) Draw the force diagram to the right. Label the forces using Fapp, FN & Fg
b) When the APPLIED FORCE is added, what happens to VELOCITY? .
c) Is the sled “accelerating”? .
2. Now, turn off the jets (slide the blue switch back to the middle) so that
there are no horizontal forces(arrows) acting on the rocket sled. *No
acceleration.
a) Draw the force diagram to the right. Use the same labels as before: FN
and Fg.
b) Is it still moving? Highlight one: YES NO
c) What do you notice about the velocity now (when there are no
horizontal arrows “forces”)? .
d) Is the sled “accelerating”? .
3. Get the rocket sled to STOP, completely. What do you have to do to stop a rightward moving rocket sled?
*Do not use the Air Drag button yet. Reloading the page doesn't count.
.
4. From the stopped position, now, slide the blue switch slightly to the right
(Fapp around 10N) to get the sled moving again. But, now, keep FRICTION OFF
and try to get it to slow down by turning on “Air Drag”. You may click the icon
for the larger drag.
a) Draw the force diagram for a rightward-moving rocket sled that is
slowing down to a stop. Do NOT use Ff
b) Check the velocity. What is happening to it? .
5. Can an object be moving to the right even though there are no rightward forces acting upon the object?
In other words, can you get it to move RIGHT, but the arrow isn’t pointing right?
(Highlight one) Yes No
It’s hard to get this to happen in our everyday life, unless you are on something very slick, like ice. Why? What opposing
“force” do we always have that makes it hard to keep an object in constant velocity? .
6. RESET the page. Slide the blue switch to the right with an APPLIED FORCE of
50N. Give it a moment to begin moving, then, turn FRICTION ON.
a) Draw the force diagram to the right. *The Ff should read (-) 50N also.
b) What do you notice about the velocity? .
c) What do you notice about the arrows? .
d) Is the sled “accelerating”? .
7. Refresh the sledder simulator. TURN ON FRICTION & AIR DRAG. Get the sled moving right for several seconds, then
switch it to left for several seconds, then back to right again. Consider the two resistance forces: Friction Force (Ff) and Air
Drag Force (Fair). What do you notice about the object’s direction versus the Ff and Fair arrow directions?
Note: Experiment for a while before you describe your answer below.
.
8. Finally, turn Friction and Air Drag OFF and try the following: Get the rocket sled moving to the right until the
speed-o-meter reaches the red zone. Then, reverse the direction of the applied force so that it is directed to the left (arrow
pointing left). Does the rocket sled immediately change direction? Explain your answer.
.
DRAWING CONCLUSIONS:
9. The force diagrams below represent five different situations. Try your best to determine which force diagram (Object)
represents each scenario/ question below.
Answer with A, B, C, D, E. *Go back to the sledder to try it to make sure your answers are correct.
Tip#1: There is a letter answer for ALL of them. Tip #2: One of the answers may be ALL OF THEM!
a. Which object(s) could be moving to the right at a constant velocity? .
b. Which object(s) could be moving to the right and accelerating right (speeding up)? .
c. Which object(s) could be moving to the right and accelerating left (slowing down)? .
d. Which object(s) could be moving to the left and accelerating right (slowing down)? .
e. Which object(s) could be moving to the right? .
10. a. Write the FULL WORDS and abbreviations for the 5 forces again (see #1):
1)
2)
3)
4)
5)
b.Which is your favorite (most useful to know) of the forces so far and why? .
