Year 12s: what will be the first way you research your future options? >>

Simple question..

i dont know how to ask this question exactly, so for example:

bob is moving. [insert strange figures and question here]

prove that the time is about 100seconds.
[insert strange working here]
Answer: t=98.4s

in this time, bob travels 50metres. what is his speed? [using]

for the second part of the question, would you use t=100 or t=98.4??

98.4

It says 'about 100s' so that the people who can't figure out the first part can still get method marks for the second part of the question.

Reply 3

ninja_penguin

Draconis

It says 'about 100s' so that the people who can't figure out the first part can still get method marks for the second part of the question.

so 98.4... thanks :biggrin:

(i have no rep power, sorry) :P:

Reply 4

Draconis

ninja_penguin

but for people who DO figure out the 1st part, which do we use? in more complex questions, this kind of difference will lead to the 2nd part's answer being e.g. either 900 and 910. this is similar but quite a big difference, nothing which is a '3sf error'.

or does it really make a difference??

In all the past papers I've done, the mark scheme has said to use the value you've calculated, ie 98.4. :smile:

Reply 5

Draconis

You might wanna have a look at a few mark schemes for your exam board, maybe it's different. I do Edexcel.

Reply 6

Elementric

Yep, always use the most precise numbers you have when working out subsequent solutions. Ideally, if 98.4 is a rounded figure you should use a couple of s.f. extra if you're giving your final answer to 3s.f.