Instantaneous velocity of an object with varying mass at the bottom of a slope

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SUMMARY

The discussion centers on the relationship between mass and speed of an object at the bottom of a slope with a constant gradient. The experiment conducted demonstrated that as the mass of the car increases, its speed at the bottom of the slope also increases. The participant initially applied the principle of conservation of energy, equating potential energy (Ep = mgh) and kinetic energy (Ek = (mv^2)/2), concluding that speed should not depend on mass. However, they later acknowledged the influence of unbalanced forces as described by Newton's second law of motion, suggesting that mass does affect acceleration and, consequently, speed.

PREREQUISITES
  • Understanding of potential energy and kinetic energy concepts
  • Familiarity with Newton's second law of motion
  • Basic knowledge of gravitational acceleration (g = 9.81 m/s²)
  • Ability to manipulate algebraic equations
NEXT STEPS
  • Explore the concept of unbalanced forces in real-world scenarios
  • Study the principles of energy conservation in physics experiments
  • Investigate the effects of friction and air resistance on object motion
  • Learn about advanced dynamics, including mass and acceleration relationships
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Students of physics, educators teaching mechanics, and anyone interested in understanding the dynamics of motion involving varying mass and forces.

zfa9675
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I conducted an experiment to investigate whether the mass of an object will affect the object speed at the bottom of a slope with a constant gradient. The experiment showed that as the mass of the object (car) increases, the speed of the car at the bottom of the slope increases.

I still do not understand why. So far, I have come up with one proof that shows I am correct:

Assuming that all the potential energy at the top of the track is converted to kinetic energy at the bottom of the track (this is similar to Gallileo's theory)
Ep=mgh
Ek=(mv^2)/2

Ep=Ek
mgh=(mv^2)/2
2mgh=mv^2
2gh=v^2

g=9.81 ms^-2

19.62h=v^2

v=\sqrt{}19.62h

Therefore, the laws of indices shows:

The speed of the object at the bottom of the slope is directly proportional to the square root of the height. Therefore, the mass of the object should not affect the speed of the car at any given point.

Can you please tell me why the mass affects the speed
 
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zfa9675 said:
I conducted an experiment to investigate whether the mass of an object will affect the object speed at the bottom of a slope with a constant gradient. The experiment showed that as the mass of the object (car) increases, the speed of the car at the bottom of the slope increases.

I still do not understand why. So far, I have come up with one proof that shows I am correct:

Assuming that all the potential energy at the top of the track is converted to kinetic energy at the bottom of the track (this is similar to Gallileo's theory)
Ep=mgh
Ek=(mv^2)/2

Ep=Ek
mgh=(mv^2)/2
2mgh=mv^2
2gh=v^2

g=9.81 ms^-2

19.62h=v^2

v=\sqrt{}19.62h

Therefore, the laws of indices shows:

The speed of the object at the bottom of the slope is directly proportional to the square root of the height. Therefore, the mass of the object should not affect the speed of the car at any given point.

Can you please tell me why the mass affects the speed

Can you think of factors that are absent from your ideal mathematical model that might be present in a real-life scenario? How about forces you haven't accounted for?
 
The other theory I had which contradicts my first one is that the weight of the car is apart of the unbalanced force which causes its acceleration down the track (Newtons second law of motion)

F(unbalanced)=ma

a=F/m

As the force increases for a constant mass, the acceleration increases. However, the mass will also increase in this cas with the force so I figured the two would even each other out and there would not be a difference in acceleration.
 

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