EMERGENCY HELP NEEDED PLZZ

[MysteRyGiRl]

heyy can sm1 plz help me out wd AS physx uncertainity question? given below
The density of the material of a rectangular block is determined by measuring the mass and
linear dimensions of the block. The table shows the results obtained, together with their
uncertainties.
mass = (25.0 ± 0.1) g
length = (5.00 ± 0.01) cm
breadth = (2.00 ± 0.01) cm
height = (1.00 ± 0.01) cm
The density is calculated to be 2.50 g cm–3.
What is the uncertainty in this result?
i hv board papers nxt ...2 nxt week n i wd rely appreciate sm1s help thank u

 

[MysteRyGiRl]

ummmm 1 more question plzz
A quantity x is to be determined from the equation
x = P – Q.
P is measured as 1.27 ± 0.02 m.
Q is measured as 0.83 ± 0.01 m.
What is the percentage uncertainty in x to one significant figure?

 

[Apoclaypse]

when solving these u have to rember one thing ,, uncertainnities are always added.! right mate!

ok on question now,, density =mass/volume,, so find v first and error in we.
V= length x width x height. 2*5*1= 10
V=10 uncertainity would be

x/10=.01/2 + .01/5 +.01/1 by solving this we get x=.17 now put this into d=m/v

x/2.5=.1/25+.17/10 uncertainty in density is .05

 

[MysteRyGiRl]

thank u soooooooo much
cd u plz answer da scnd 1 too?

 

[Apoclaypse]

Subtract p from q and add their uncertainity!! 1.27-.83=.44 .01+.02=.03
x=.44±.03

 

[Apoclaypse]

there u go!

 

[thunderingthunder]

ummmm 1 more question plzz
A quantity x is to be determined from the equation
x = P – Q.
P is measured as 1.27 ± 0.02 m.
Q is measured as 0.83 ± 0.01 m.
What is the percentage uncertainty in x to one significant figure?

ATC:x=P-Q..
So....x=1.27-0.83=0.44....
%age uncertainty is (error in x/x)x100....we dont have error in x..we will calculate it...lyk this:
error in x/x=error in P/P+error in Q/Q
error in x=0.01..
therefore %age uncertainty in x=(0.01/0.44)x100=2.2%..
therefore %age uncertainty in x=2.2%..
hope this helps

 

[MysteRyGiRl]

ummm da answer 4 da second question is supposed 2 b 7% :shock:
hw do v get dat???
btw thnx 4 helping out

 

[Xenon]

maybe thundering thunder made a typing mistake, the error in x will be 0.03 (0.02 + 0.01 )instead on 0.01. this will give u a value of 6.8%.

 

[MysteRyGiRl]

ohhhkk
thanx guyzz

 

[thunderingthunder]

maybe thundering thunder made a typing mistake, the error in x will be 0.03 (0.02 + 0.01 )instead on 0.01. this will give u a value of 6.8%.

YEAH!!i agree--->