Transcript Driving - amart612

Introduction: While you were
driving, have you ever felt like you
would fly out of your vehicle as
you are going around a turn if the
door was not there? Find out why
when you discover the difference
between centrifugal and
centripetal forces. Grab a paper
and pencil and let’s get started!!
Task
Procedure
Evaluation
Conclusion
Teacher’s Page
①Figure out the difference between
Centripetal and Centrifugal Force.
②Find the average mass of your
favorite type of vehicle and round it
to the nearest 100kilograms.
③Pick a velocity at which you would
like to go around a turn. (as a
multiple of 5m/s)
④Figure out the force exerted on the
car as you take the turn.
⑤Find the force keeping the car on
the road. (gravitational force, use
g=10m/s^2)
⑥Does your vehicle stay on it’s
wheels or flip over and fly off the
road?
(Write the mass and velocity(speed)
your use on top of your paper)
①
Read about Centripetal and Centrifugal Force.
Decide which force you are solving for.
②
Pick your favorite type of vehicle, what is the
average mass of that type? (for a car use
3000lbs, SUV 4000lbs, truck 5000lbs)
③
Use a unit converter to put the mass in
kilograms (round to nearest 100kilograms).
Use the equation w=mg where w is the weight,
m is the mass, and g is the value of gravity.
④
Pick a velocity and convert it to m/s (round to
nearest 5m/s)
⑤
Find the force exerted on the car as you take
the turn in Newtons (N) using the equation
Fc=(mv2)/r, where m is the mass of the car, v is
the velocity/speed of the car, and r is the
radius of the turn (use r=10m).
⑥
Find the force keeping the car on the road in
Newtons (N). Use the equation Fg=mg. (Hint:
you already have this number)
⑦
So, does your car flip or make the turn?
•
Hand in the paper used to solve
the force problem. At the top of
this paper write either
“Centrifugal” or “Centripetal” as
the force you have just solved
for.
•
You’ll be evaluated on
correctness of the problem and
labeling the force correctly. And
for stating if your vehicle stays
on the road or not.

“Centrifugal force” isn’t a real force but a
misconception. It is just a label for what you
think you are feeling as you go around a turn.
The fact is that it the centripetal force that you
feel that actually acts towards the center of the
turn. The “centrifugal force” is the label for the
outward feeling that seems to perceived.

Now look at this!! Fc=(mv2)/r and Fg=mg and the
tipping point would be where Fc=Fg. So if you set
these two equations together you get;
(mv2)/r=mg and the m in both equations cancel
out. The mass of the vehicle has nothing to do
with whether it flips or not!!! Pretty Cool! So, if
v>(gr)1/2 then you will flip but if v<(gr)1/2 then
you won’t. However if v=(gr)1/2 your guess is as
good as mine for what happens; depends how
lucky you are!

Bonus 1: Use the newly found parameters above
and plug in g, r, and v to see if you get the same
result. i.e. Flip or not?

Bonus 2: Now that you know what force is at play
when dealing with circular motion, can you
name other places/things that involve circular
motion?

Objective: Students will relate centripetal force to real life

PA- Pennsylvania Academic Standard
through solving the car problem. They will calculate the
centripetal force on the car going around a turn and specify
whether the car completes the turn or not. The students will
review the given sights to get a better understanding on
centripetal and centrifugal forces. The students will hand in
their results to be evaluated for correctness and
comprehension.

Subject : Science and Technology


Grade 3.4.12: Grade 12


Area 3.4: Physical Science, Chemistry and Physics
Standard C.: Apply the principles of motion and force.

•Analyze the principles of rotational motion to solve problems relating to
angular momentum, and torque.

•Interpret a model that illustrates circular motion and acceleration.
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