# HW17 - schneiter(tcs639 – HW17 – Ross –(89152 1 This...

This preview shows pages 1–2. Sign up to view the full content.

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

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: schneiter (tcs639) – HW17 – Ross – (89152) 1 This print-out should have 12 questions. Multiple-choice questions may continue on the next column or page – find all choices before answering. 001 (part 1 of 3) 10.0 points A force vector F = F x ˆ i + F y ˆ j + F z ˆ k acts on a particle located at vector X = ( x, y, z ). Given F x = − 31 N, F y = 7 . 97 N, F z = − 86 . 1 N, x = 8 . 43 m, y = − 3 . 71 m and z = − 8 . 02 m, calculate the three components of the torque vector vector τ = τ x ˆ i + τ y ˆ j + τ z ˆ k . First, calculate the τ x component. Correct answer: 383 . 35 N m. Explanation: The torque vector is defined as the cross product vector τ = vector X × vector F . In components, this means τ x = y F z − z F y = 383 . 35 N m , τ y = z F x − x F z = 974 . 443 N m , τ z = x F y − y F x = − 47 . 8229 N m . 002 (part 2 of 3) 10.0 points Second, calculate the τ y component. Correct answer: 974 . 443 N m. Explanation: See above. 003 (part 3 of 3) 10.0 points Finally, calculate the τ z component. Correct answer: − 47 . 8229 N m. Explanation: See above. 004 (part 1 of 2) 10.0 points A cylinder with moment of inertia 28 . 7 kg m 2 rotates with angular velocity 8 . 01 rad / s on a frictionless vertical axle. A second cylin- der, with moment of inertia 26 kg m 2 , initially not rotating, drops onto the first cylinder and remains in contact. Since the surfaces are rough, the two eventually reach the same an- gular velocity. I 2 I 1 ω Before ω After Calculate the final angular velocity. Correct answer: 4 . 20269 rad / s. Explanation: From conservation of angular momentum ( I 1 + I 2 ) ω = I 1 ω , or ω = I 1 I 1 + I 2 ω = (28 . 7 kg m 2 ) (28 . 7 kg m 2 ) + (26 kg m 2 ) (8 . 01 rad / s) = 4 . 20269 rad / s ....
View Full Document

## This note was uploaded on 04/23/2009 for the course PHYS 152 taught by Professor Button during the Spring '08 term at IUPUI.

### Page1 / 4

HW17 - schneiter(tcs639 – HW17 – Ross –(89152 1 This...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online