Qualification > Sciences
P.H.Y.S.I.C.S P2 D.O.U.B.T.S CIE
halosh92:
nov 2007
Q4d
nov 2005
Q4ai, ii
in the ms its 42+/- 4 cm/s
dont we have to change it to meters ?
and where did they get the +/-4 from
similarly for the second part, where did they get that uncertainity from?
Meticulous:
--- Quote from: halosh92 on June 02, 2010, 08:20:35 am ---nov 2007
Q4d
--- End quote ---
It's exactly like the steel and concrete combination. Why is concrete stronger in compression and weaker in tension? Because in tension the extensions of top and bottom layers vary, and so it shatters. The opposite goes for steel.
The exact same case here. However, the difference in extensions in the thicker rod is greater, and so it breaks easier. i.e require less bending.
Meticulous:
--- Quote from: halosh92 on June 02, 2010, 08:20:35 am ---
nov 2005
Q4ai, ii
in the ms its 42+/- 4 cm/s
dont we have to change it to meters ?
and where did they get the +/-4 from
similarly for the second part, where did they get that uncertainity from?
--- End quote ---
No you don't have to change them to meters. Actually, it's preferable to keep them as it's given to you! It's given to you in cm, then keep it in cm. BUT, if you change it to meters, it would still be right. However, the probability of making an error is increased as now you have to divide by a 100 (you could type 10 in your calculator)
And, for the second part, it's not uncertainty. It's just the range of ACCEPTABLE values by students, as your answer varies from another's. It's not for you, it's for the examiners. As long as your answer lies in the range, you're safe.
Meticulous:
Was I clear ? ::)
halosh92:
--- Quote from: ~ A.F ~ on June 02, 2010, 08:49:39 am ---No you don't have to change them to meters. Actually, it's preferable to keep them as it's given to you! It's given to you in cm, then keep it in cm. BUT, if you change it to meters, it would still be right. However, the probability of making an error is increased as now you have to divide by a 100 (you could type 10 in your calculator)
And, for the second part, it's not uncertainty. It's just the range of ACCEPTABLE values by students, as your answer varies from another's. It's not for you, it's for the examiners. As long as your answer lies in the range, you're safe.
--- End quote ---
so basically the +/-4 is not the uncertainity.
and for this question the final answer MUST be in m.
so i have to divide 42 by 100 ..correct?
THX A BUNCH ;D
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