HW3-solutions

# HW3-solutions - Agha (sa9896) – HW3 – bohm – (59970)...

This preview shows pages 1–3. 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: Agha (sa9896) – HW3 – bohm – (59970) 1 This print-out should have 11 questions. Multiple-choice questions may continue on the next column or page – find all choices before answering. 001 (part 1 of 2) 10.0 points A pedestrian moves 4 km east and then 17 km north. Find the magnitude of the resultant dis- placement vector. Correct answer: 17 . 4642 km. Explanation: Using the Pythagorean theorem, we find the magnitude of the displacement vector: R = radicalbig x 2 + y 2 The direction is given by: θ = arctan parenleftBig y x parenrightBig 002 (part 2 of 2) 10.0 points What is the direction of the displacement vec- tor (using the counter-clockwise angular di- rection to be positive, within the limits of − 180 ◦ to +180 ◦ )? Correct answer: 76 . 7595 ◦ . Explanation: 003 10.0 points All angles are measured in a counter- clockwise direction from the positive x-axis. A hiker makes four straight-line walks ( A , B , C , and D ) in random directions and lengths starting at position (41 km , 41 km) , listed below and shown below in the plot. A 24 km at 62 ◦ B 33 km at 180 ◦ C 23 km at 90 ◦ D 16 km at 30 ◦ A B C D Figure: Drawn to scale. How far from the starting point is the hiker after these four legs of the hike? Correct answer: 52 . 7817 km. Explanation: A B C θ e D E Scale: 10 km = Note: bardbl vector E bardbl = 52 . 7817 km and θ e = 278 . 582 ◦ . Δ a x = (24 km) cos62 ◦ = 11 . 2673 km , Δ a y = (24 km) sin62 ◦ = 21 . 1907 km , Δ b x = (33 km) cos180 ◦ = − 33 km , Δ b y = (33 km) sin180 ◦ = − 4 . 44315 × 10 − 5 km , Agha (sa9896) – HW3 – bohm – (59970) 2 Δ c...
View Full Document

## This note was uploaded on 11/03/2008 for the course PHY 302K taught by Professor Kaplunovsky during the Spring '08 term at University of Texas at Austin.

### Page1 / 5

HW3-solutions - Agha (sa9896) – HW3 – bohm – (59970)...

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

View Full Document
Ask a homework question - tutors are online