If you could give answers with significant figures it would be appreciated A pre
ID: 2995839 • Letter: I
Question
If you could give answers with significant figures it would be appreciated
A precision micrometer can measure dimensional changes of 0.001 mm. If a steel rod is warmed by 4.5 degree C by holding it in the hand while being measured, will this warming affect the measured length? The original cooler length is 25.89 mm. [You may assume a = 11 Times 10-6 K-1. Please note: you must justify/prove your answer to gain any marks] A uniform steel circular post 6 m long is designed to support a mass of 2500 kg, allowing for a maximum compression of 1.5 mm. Calculate the minimum diameter of the post. [Youngs Modulus Y (or E) for steel = 2 Times 1011 Nm-2]Explanation / Answer
a)change in length=l0*alpha*deltaT
=25.89*11*10^-6*4.5
=0.00128
Yes tis warming effect is measured by the micrometer
b.)2500*g/A=(2*10^11*1.5*10^-3)/(6)
A=4.9*10^-4
A=pi*d^2/4
d=0.025 m ans