hey guys physics cie help .please

[cashem'up]

In an experiment, a radio-controlled car takes 2.50 ± 0.05 s to travel 40.0 ± 0.1 m.
What is the car’s average speed and the uncertainty in this value?..........

m getting 0.36 but markscheme says 0.4

[*Hope*]

oh this is in paper 1 right?
ok u see the minimum number of significant figures in the uncertainity is 2 (if u include the zeros)
so the actual answer is 0.36 but we must round to 2 s.f so we will get 0.4
hope i helped!

[Amr Fouad]

Thanks lolo

+ rep. for helping others

[nid404]

ohh....so uncertainties always have to be 2sf....i wsn;t aware of that either.

[*Hope*]

No it actually depends on the given values in the question but always round to the least number of s.f given in the question
Thanks for +rep

[cashem'up]

thanks but why i was shocked was in the mcq options there were both values 0.36 and 0.4 , and even in the ER the examiner mentions 0.4 but then if there is an option 0.36 shouldnt it be correct

[Amr Fouad]

No way .36 is a correct answer..its not a rule to be 0.4..

check the s.f of the given in the question..all uncertainties to 1s.f..so shud be the answer

[cashem'up]

hey one more doubt..........in w05 question  7 how would ya go abt doing this

[cashem'up]

No way .36 is a correct answer..its not a rule to be 0.4..

check the s.f of the given in the question..all uncertainties to 1s.f..so shud be the answer

hey i agree but see da paper n da ER will upload for ya chek it out.........

[cashem'up]

and its question 4

[Nobody]

read this.... For Q.4 & answer is C

Accuracy is defined as, "The ability of a measurement to match the actual value of the quantity being measured". If in reality it is 34.0 F outside and a temperature sensor reads 34.0 F, then than sensor is accurate.

Precision is defined as, "(1) The ability of a measurement to be consistently reproduced" and "(2) The number of significant digits to which a value has been reliably measured". If on several tests the temperature sensor matches the actual temperature while the actual temperature is held constant, then the temperature sensor is precise. By the second definition, the number 3.1415 is more precise than the number 3.14.

Found it on internet..
hope i helped!

[cashem'up]

hey nobody.....lol that kinda funny neways
yea thanks but i  mean i was question 4 to the 2nd paper the 1st paper i wanted Q7help thanks a ton newasy

[Nobody]

hey nobody.....lol that kinda funny neways
yea thanks but i  mean i was question 4 to the 2nd paper the 1st paper i wanted Q7help thanks a ton newasy

oh...my bad..

[cashem'up]

hey can someone please clear these doubts thankx

[astarmathsandphysics]

I also dont get 0.36 for question 4