Lect_15_Statics_Stress_and_Strain

Lect_15_Statics_Stress_and_Strain - Lecture 15- Static...

Info iconThis preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Lecture 15- Static Equilibrium- Elasticity, Stress and Strain Conditions for equilibrium: F net = net = Equilibrium Equilibrium A system is in equilibrium if no part of it is moving (or moving at constant rate.). and CG is at rest Parts are not moving about the CG. A very useful feature: The system should not rotate about ANY axis. We can take the torques about any point we like . Example: Board on scales A 1.00 m long board with a mass of 5.00 kg is supported at each end by a scale. A 10.0-kg mass is placed 25.0 cm from the left side. What value does each scale read? L = 1.00 m M = 10.0 kg m = 5.00 kg d = 25.0 cm A. 15.0 kg (L), 0 kg (R) B. 12.5 kg (L), 2.50 kg (R) C. 10.0 kg (L), 5.00 kg (R) D. 7.50 kg (L), 7.50 kg (R) E. 5.00 kg (L), 10.0 kg (R) d = 25.0 cm L = 1.00 m M = 10.0 kg m = 5.00 kg N 1 N 2 mg Mg L /2 2 equations, 2 unknowns N 1 N 2 Mg mg = F net = Let us take the torque about the left end: L N 2 dMg L 2 mg = net = N 1 g = M m N 2 g On the left On the right DEMO: Plank and scales Answer C d = 25.0 cm L = 1.00 m M = 10.0 kg m = 5.00 kg N 1 N 2 mg Mg L /2 N 1 N 2 Mg mg = L N 2 dMg L 2 mg = N 2 g = M d L m 2 = 10.0kg 25.0cm 100cm 5.00kg 2 = 5.00kg = 5.00kg 10.0kg 5.00kg = 10.0kg ACT: How to weight a turkey on a tiny kitchen scale You bought a frozen turkey and forgot how many pounds it was. All you have is a tiny kitchen scale that can weigh a maximum of 2 lb. But heres a good trick you can use to get an estimation turkey Light rod scale d L When d = 20 cm , the scale reads 2 lb exactly. If L = 1 m , how big is your turkey?...
View Full Document

Page1 / 30

Lect_15_Statics_Stress_and_Strain - Lecture 15- Static...

This preview shows document pages 1 - 8. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online