A metal rod has a length of 100cm at 200\(^oC\). At what temperature will its length be 99.4cm. If the linear expansivity of the material of the rod is 2 x 10\(^{-5}C^{-1}\)

Promix_Ose

1 year ago

L1 = 100cm, T1 = 200°C
L2 = 99.4cm, T2= ?
α = 2 x 10−5C−1
α = 0.00002
α = L2−L1 / L1(T2−T1)

0.00002 = 99.4−100 / 100(T2−200)
0.00002 = −0.6 / (100T2−20000)
0.00002 (100T2−20000)= −0.6
0.002T2 - 0.4 = −0.6
0.002T2=-0.6+0.4
T2 = -0.2/0.002
T2 = -100°C

Bene1

6 years ago

There is a problem with the numbers and also why -100 and not 100

SedooAzoom

4 years ago

The Explanation is correct because thae final lengthis 99.4cm so that means the chane in legth will be 99.4-100=-0.6cm

Susanaogozi

6 years ago

Answer is 300

Luck_Jon

5 years ago

The formula you gave and the substitution you did using the formula does not align
It says L2-L1 over L1(t1-t2) but you used the L2 which Is 99.4cm as L1 which is 100cm

Themitayo

5 years ago

In your solution L2 is supposed to be 99.4cm not 100cm
99.4-100 =-0.6cm

Cassablanca

4 years ago

Why is 200 subtracting T2 and 100 multiplying (T2-T1) instead of 99.4

Ugwuodo

5 years ago

Error in calculations

Shedvector

5 years ago

The explanation is wrong