Sunday, August 12, 2007 - :

Hooray!! Finish doing 06/07 Semester 1 and 2 past year papers for Mechanics.
06/07 S1 : 96/100
06/07 S2 : 100/100 =d
of coz i did it while looking at the answers xD
Stupid Q2 in 06/07 S1.. ask about the % change in torsional stiffness.. nvr even give G or θ or L.. i donnoe of other mtd then T/θ as the torsional stiffness.. haiz..
If any1 knows how to do that question.. please tell me T_T

Here.. i'll put up that question..

Q2. A hollow shaft of 70 mm outer diameter and 10 mm thickness is made from a material that withstands a maximum shear stress of 45 MN/m2.

(a) For a speed of 600 rpm calculate the torque and the power which can be transmitted by the shaft. (5 marks)
(b) If the shaft is replaced by a solid shaft of the same weight and material, find the required diameter and hence the torque that can be transmitted.
(5 marks)
(c) Find the percentage change in the torsional stiffness, (T/θ) of the solid shaft.
(4 marks)

yea.. i did the first 2 part already.. here's the answer for the question

Q2	a) T = 2241.75 Nm ; P = 140.85 kW ( D = 70 mm ; d = 50 mm ) b) D = 48.99 mm ; T = 1039 Nm c) % change in (T/θ) = 67.6 %

so yeah.. if you got any clue how to do that stupid Torsional Stiffness question, do send me a mail or call me =d

Shana, Flame-Haired Red-Hot-Eyed Hunter 9:29 PM