{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

hw2_solns

# hw2_solns - Answer Key Homework 2 David McIntyre 45123 This...

This preview shows pages 1–3. Sign up to view the full content.

Answer, Key – Homework 2 – David McIntyre – 45123 – Mar 25, 2004 1 This print-out should have 15 questions. Multiple-choice questions may continue on the next column or page – fnd all choices beFore making your selection. The due time is Central time. Chapter 2 problems. 001 (part 1 oF 1) 0 points The graph below shows the velocity v as a Function oF time t For an object moving in a straight line. t O v Which oF the Following graphs shows the corresponding displacement x as a Function oF time t For the same time interval? 1. t O x 2. t O x 3. t O x 4. t O x correct 5. t O x Explanation: The displacement is the integral oF the ve- locity with respect to time ~x = Z ~v dt . Because the velocity increases linearly From zero at frst, then remains constant, then de- creases linearly to zero, the displacement will increase at frst proportional to time squared, then increase linearly, and then increase pro- portional to negative time squared. ±rom these Facts, we can obtain the correct answer. 002 (part 1 oF 2) 5 points A particle moves according to the equation x = (10 m / s 2 ) t 2 where x is in meters and t is in seconds. ±ind the average velocity For the time in- terval From t 1 = 2 . 1 s to t 2 = 3 . 95 s. Correct answer: 60 . 5 m / s. Explanation: x = (10 m / s 2 ) t 2 v ave = Δ x Δ t = (10 m / s 2 ) ( t 2 2 - t 2 1 ) t 2 - t 1 = (10 m / s 2 ) [(3 . 95 s) 2 - (2 . 1 s) 2 ] (3 . 95 s) - (2 . 1 s) = 60 . 5 m / s 003 (part 2 oF 2) 5 points ±ind the average velocity For the time interval From t 1 = 2 . 1 s to t 3 = 2 . 2 s. Correct answer: 43 m / s. Explanation: v ave = Δ x Δ t = (10 m / s 2 ) ( t 2 3 - t 2 1 ) t 3 - t 1 = (10 m / s 2 ) [(2 . 2 s) 2 - (2 . 1 s) 2 ] (2 . 2 s) - (2 . 1 s) = 43 m / s 004 (part 1 oF 1) 0 points The acceleration oF an object, starting From rest, is shown on the graph below.

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

View Full Document
Answer, Key – Homework 2 – David McIntyre – 45123 – Mar 25, 2004 2 t(s) a(m/s 2 ) 5 -5 1 2 3 4 5 Other than at t = 0, when is the velocity of the object equal to zero? 1.
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 5

hw2_solns - Answer Key Homework 2 David McIntyre 45123 This...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online