Find Acceleration Experimentally

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In summary, the conversation discusses different equations that can be used to find acceleration when given displacement and time. One method involves using the formula a = 2(Δx - Vit)/t^2, while the other involves using the equations v = Δx/Δt and a = Δv/Δt. However, these methods may result in different values for acceleration. It is suggested that using Newton's second law (F=ma) may be easier and more accurate in determining the acceleration of an object.
  • #1
Power of One
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You drop an object. You take the time it takes to hit the ground. So you have Δx (displacement) and time.

To find acceleration do you use

xf= xi + Vi t + .5at2
Δ x= Vi t + .5at2
Δ x- Vi t=.5at2
a= 2(Δ x- Vit )/ t2

or do you use

v= Δ x/ Δ t
a= Δ v/ Δ t

Should acceleration come out the same? Why do they differ so much? Take example a Δx of 2m and a time of .5. Using the first equation you get 16 m/s^2. But using the second method, you get 8 m/s^2.
 
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  • #2
It seems to me that you're not given enough information. If you had the initial and final velocity, you could plug into

[tex] V_{f} = V_{i} + at[/tex]

to experimentally find the acceleration.

What would be easier is to use Newton's second law (F=ma) since then you only need to know the object's mass and the force it exerts on the ground upon impact to experimentally determine the value of g.
 
  • #3


I would like to clarify that both methods are correct and can be used to find acceleration experimentally. However, the first equation (xf= xi + Vi t + .5at2) is more accurate as it takes into account the initial velocity (Vi). The second equation (a= Δ v/ Δ t) assumes that the initial velocity is zero, which may not be the case in all scenarios.

In the example given, the difference in the values of acceleration obtained using the two equations is due to the initial velocity (Vi) being ignored in the second equation. This can significantly affect the accuracy of the results, especially for larger displacement and time values.

To ensure the most accurate results, it is important to consider all relevant variables, including initial velocity, in the equations used to find acceleration experimentally. Both equations are valid, but the first one provides a more comprehensive and accurate approach.
 

1. How do you measure acceleration experimentally?

To measure acceleration experimentally, you will need a timer, a motion sensor, and an object to test. The motion sensor should be placed at the starting point of the object's motion. Start the timer and release the object from the motion sensor's range. The motion sensor will track the object's motion and the timer will record the time it takes for the object to reach the end point. Using the formula a = (vf-vi)/t, you can calculate the acceleration of the object.

2. What is the difference between average and instantaneous acceleration?

Average acceleration is the change in velocity over a period of time, while instantaneous acceleration is the acceleration at a specific moment in time. Average acceleration is calculated by dividing the change in velocity by the total time, while instantaneous acceleration is calculated using the derivative of the velocity-time graph at a specific point.

3. How does the mass of an object affect its acceleration?

The mass of an object does not directly affect its acceleration. According to Newton's Second Law of Motion, the acceleration of an object is directly proportional to the net force acting on it, and inversely proportional to its mass. This means that a larger mass will require a greater force to accelerate it at the same rate as a smaller mass.

4. What are some sources of error when measuring acceleration experimentally?

Some sources of error when measuring acceleration experimentally include air resistance, friction, and human error. Air resistance can slow down the object's motion, leading to inaccurate results. Friction between the object and the surface it is moving on can also affect its acceleration. Human error, such as starting or stopping the timer at the wrong time, can also lead to inaccurate measurements.

5. How can you improve the accuracy of an acceleration experiment?

To improve the accuracy of an acceleration experiment, you can repeat the experiment multiple times and take the average of the results. This can help to reduce the impact of any random errors. You can also increase the distance over which the object is accelerating to minimize the effect of any external factors such as air resistance. Using high-quality equipment and carefully controlling the experimental conditions can also help to improve the accuracy of the results.

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