How Do You Calculate Speed and Uncertainty with Given Measurements?

  • Thread starter Thread starter Alipepsi
  • Start date Start date
  • Tags Tags
    Uncertainty
AI Thread Summary
To calculate speed and uncertainty, the formula v = d/t is used, where distance is 228 cm with an uncertainty of ±0.5 cm and time is 2.99 s with an uncertainty of ±0.5 s. The user conducted 15 trials, yielding a total speed of 44.99 s, leading to an average speed of 2.99 m/s. The user attempted to calculate the percentage uncertainties for both distance and time, resulting in confusion over the final speed calculation. Assistance is sought to clarify the correct method for determining speed and its associated uncertainties.
Alipepsi
Messages
14
Reaction score
0

Homework Statement


Hey there, I need some help with uncertainties and how to find the speed of a moving object. I have tried to solve the problem several times but my answer seems to be wrong.

Formula for speed : v=d/t
My uncertainties: 0.5cm (distance) and 0.5s for time. The uncertainties were measured with the same analog.
I did the experiment 15 times and got different speed result of the object each time. The total sum of the speeds ( 15 trials) was 44.99s. The average of that is 2.99 (15/44.99)
Oh and my measuring device was 228cm long (exact)

I need to find out the speed and the uncertainties
If I missed any detail please please let me know
PLEASE HELP! I'am very frustrated right now..=S


Homework Equations



Formula to use : v=d/t

The Attempt at a Solution



v=d/t
= (228 +\- 0.5)m/(2.99+\- 0.5)s
228 divided by 0.5 = 456%
2.99 divided by 0.5= 5.78%
456% +5.78%=461.98%

so now 461.98% * 76.2 ( which I got by diving 288 and 2.99)
my final answer was v=76.25m? +\- 39%..
I'am confused..
 
Physics news on Phys.org
Actually spend hours on trying to solve this :S
Help will be greatly appreciated!
 
anyone?
 
Check out this site here: http://www.rit.edu/cos/uphysics/uncertainties/Uncertaintiespart2.html
 
Last edited by a moderator:
Okey, thanks
 
Thread 'Voltmeter readings for this circuit with switches'

Thread 'Voltmeter readings for this circuit with switches'

TL;DR Summary: I would like to know the voltmeter readings on the two resistors separately in the picture in the following cases , When one of the keys is closed When both of them are opened (Knowing that the battery has negligible internal resistance) My thoughts for the first case , one of them must be 12 volt while the other is 0 The second case we'll I think both voltmeter readings should be 12 volt since they are both parallel to the battery and they involve the key within what the...
View full post »
Thread 'Correct statement about a reservoir with an outlet pipe'

Thread 'Correct statement about a reservoir with an outlet pipe'

The answer to this question is statements (ii) and (iv) are correct. (i) This is FALSE because the speed of water in the tap is greater than speed at the water surface (ii) I don't even understand this statement. What does the "seal" part have to do with water flowing out? Won't the water still flow out through the tap until the tank is empty whether the reservoir is sealed or not? (iii) In my opinion, this statement would be correct. Increasing the gravitational potential energy of the...
View full post »

Similar threads

Finding uncertainty of a measurement
Replies
1
Views
1K
Help calculating the uncertainty in the Sun's rotational speed
Replies
4
Views
2K
How to Combine Gradient Uncertainty with other Uncertainty?
Replies
3
Views
2K
I Reported uncertainties for time and distance in physics experiment
Replies
1
Views
1K
When Do I Use Reading Error in Measurement Uncertainty?
Replies
8
Views
2K
Understanding Time Measurement in Physics: Uncertainty and Calculations
Replies
6
Views
2K
B Energy-time uncertainty relation for a volume and macroscopic objects?
Replies
2
Views
474
How to appropriately assign sigma values (uncertainty)
Replies
9
Views
2K
How to Calculate Resistors in Parallel Uncertainty
Replies
3
Views
5K
Propagating uncertainty when calculating acceleration due to gravity?
Replies
3
Views
11K

Hot Threads

Recent Insights

Back
Top