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Results & Interpretation
Relationship between ‘force’ and ‘motion’ was studied and findings are interpreted with reference to Newton’s Three Laws of Motion.
Experimental data and results support the hypothesis that: The stopping distance of an automobile in its ‘natural motion’ varies when it travels on different surfaces and incline plane.
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When the string was attached to the can of coke car traveled in a circle on each of the five surfaces. The string’s tension generated centripetal force causing the car to move in a constant circular path (Abbott 1981, NASA, 1999). When not constrained by the string, the car resumed its "natural motion" and traveled in a straight line for each of the surfaces.
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Source: http://www.physicsclassroom.com
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We experience these phenomena in our life as our parents’ car travels around a curve it experiences frictional force towards the center. If there is no friction (i.e., ice covered road) the car travels in a straight line or “skids off the road”.
Findings are explained by
Newton’s First law of Motion
an object in motion stays in motion
unless acted upon by a net force.
Higher values of Coefficient of Static Friction versus Coefficient of Kinetic Friction indicate that it is indeed interaction between these frictional forces keeps the cars from toppling on an incline plane. This is (Newton and Abbott, 1999) why drivers are cautioned to drive slowly when going down hill, and why a slippery slope is a ‘slippery slope’!
On the other hand, when the car was set to run on surfaces that provided fairly high resistance, the static friction, counteracted the kinetic friction of the car. The stopping distance was very short.
This explains “stuck in the mud” phenomena or why cars, trucks and even human beings find it very difficult
to move on slush, and
surfaces having large
sized grit. Findings are
supported by Newton’s
Second Law of Motion.
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This experiment was extended then to study the
nature of force – Action Force (AF) and
the Reaction Force (RF).
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Source: http://www.physicsclassroom.com
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Source: http://www.physicsclassroom.com |
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A balloon-propelled car was raced. As the air escaped
backwards from the balloon (Action Force) and the
car ran forwards as a result of Reaction Force of the escaping air.
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The stopping distance of the car varied with the type of surface and angle of incline. On smooth surfaces the car’s wheels skidded a few inches before coming to a complete stop - when Coefficient of Static Friction became greater than Coefficient of Kinetic Friction.
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As all air from the balloon escaped, the car stopped moving on all five surfaces - demonstrating that a
force being exerted by escaping
air. The findings are consistent
with Newton’s Third Law of Motion:
for every force there is an equal
and opposite force.
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Source: http://www.physicsclassroom.com
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Results of this experiment successfully demonstrate that:
The toy cars, though having non-complicated design, move according to Newton’s Laws of Motion.
The Laws of Motion, discovered by Sir Issac Newton more than two hundred years ago, are applicable universally to all objects in motion
Experimental data and findings support the hypothesis that the stopping distance of an automobile in its ‘natural motion’ does vary when it travels on different surfaces and incline plane. Findings are interpreted and explained with reference to Newton’s Three Laws of Motion.
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