Uncertainty in percentage

[Chinyere Okeke 2J]

What is the uncertainty when it is in percentage. Like for example, if a problem says an e- has a velocity of 4.5 m/s with an uncertainty of 1% is the delta-v 1 or is it 4.5(0.01)?

[John Pham 3L]

That should be correct. You just multiply the percentage to the value given to find the uncertainty.

[Leo Naylor 2F]

The delta-v is 4.5(0.01), as you guessed. Multiply the percentage uncertainty by the velocity to find the absolute uncertainty.

[Christine Ma 3L]

Whenever you're unsure, you can also use the units to help you. Uncertainty in velocity (Δv) should have the units m/s so you would multiply the % by the velocity to get the uncertainty in velocity in meters per second. Hope this helps.

[Khoa Vu 3l]

Adding on to what the other posts have said, multiplying your velocity by the decimal form of your percentage should yield the change in velocity. However, you should keep in mind that for uncertainties, the uncertainty can be both additive and subtractive. For example, the 1% uncertainty of 4.5 is .045. This could mean that the velocity is either 4.545 or 4.455. You would need to find the difference between these two velocities in order to get the absolute velocity change.

[Arya Adibi 1K]

The percentage uncertainty represents the percent of the originally velocity that is uncertain. So in this case it would be 4.5 m/s +/- 0.01(4.5 m/s)

[IshanModiDis2L]

That should be correct but I would also suggest using the units to check your work when doing it.

[Kyle Dizon 3A]

Relying on the units will help with your confusion. Also, you can attempt to multiply the percentage to find the value of the uncertainty.

[Susanna Givan 2B]

Multiplying is the correct procedure, then? Thank you so much for your clarification, it really helped me understand percentage uncertainty.