physics help needed........plz

[ashwinkandel]

6 significant figures. You ignore the last 0.
Usually its to 3.

ending zero after decimal point is significant , isn't it?

[iluvme]

You mean the last zero?
Yes.

[ashwinkandel]

if the last digit was significant then why did u say 6 s.f. there should have been 7 isn't it? and you have said ignore last 0. how can we ignore it if it is significant?

[iluvme]

if the last digit was significant then why did u say 6 s.f. there should have been 7 isn't it? and you have said ignore last 0. how can we ignore it if it is significant?

Damn.My mistake, No it is not significant. Sorry.

[Deadly_king]

Damn.My mistake, No it is not significant. Sorry.

Nope......ashwin is right there. Indeed the number is correct to 7 sf.

Since the zero has been written and is after decimal point, it is certainly significant.

Otherwise the last zero would not have been written to form a number correct to 6 sf.

I apologise for my mistake

Example : Express 1.99 correct to 2sf ----> 2.0

The zero counts as a significant figure.

I had already stated this example before 

[ashwinkandel]

one more question related to this:
5 A student makes measurements from which she calculates the speed of sound as 327.66ms–1.
She estimates that her result is accurate to ±3 %.
Which of the following gives her result expressed to the appropriate number of significant figures?
A 327.7ms–1 B 328ms–1 C 330ms–1 D 300ms–1

[elemis]

Is it D ?

Which year ?

[ashwinkandel]

ya it is D . Can you explain me how is it D?

[elemis]

ya it is D . Can you explain me how is it D?

I THINK this is the explanation :

Since the uncertainty is given to a maximum of 1 s.f. therefore the actual answer should also be given to an accuracy of 1 SF.

Hence, answer = D

What year is this question from ?

[ashwinkandel]

thanks for the explanation. this question was from CIE 2003 May/June paper 1.

[elemis]

Dude, the MS says the answer is C

How could say I was correct ? My answer and explanation is wrong.

[ashwinkandel]

ohh i m really sorry. i apolologise for this i mistakely looked another marking scheme.

[elemis]

ohh i m really sorry. i apolologise for this i mistakely looked another marking scheme.

I'll be honest too... I really dont know how its C

[Deadly_king]

one more question related to this:
5 A student makes measurements from which she calculates the speed of sound as 327.66ms–1.
She estimates that her result is accurate to ±3 %.
Which of the following gives her result expressed to the appropriate number of significant figures?
A 327.7ms–1 B 328ms–1 C 330ms–1 D 300ms–1

Let delta C = c where C is the speed of sound.

% uncertainty = c/C * 100
                 3 = c/327.66 * 100 ---> c = 9.8

But c is taken as 10 since the % uncertainty (3%) is given correct to 1 significant figure.

Therefore the correct answer should be to the nearest tenth which results in C = 330 m/s

Hope you understood what I am trying to say

[ashwinkandel]

you are great deadly_king. thanks again .