This preview shows pages 1–4. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: homework 04 GAUTHIER, JOSEPH Due: Sep 28 2007, 1:00 am 1 Question 1, chap 5, sect 1. part 1 of 2 10 points Four forces act on a hotair balloon, as shown from the side. 1020 N 480 N 1285N 569N Note: Figure is not drawn to scale Draw the vectors to scale on a graph to determine the answer. a) Find the magnitude of the resultant force on the balloon. Correct answer: 896 . 803 N (tolerance 5 %). Explanation: 1020 N 480 N 1285 N 569 N 8 9 6 . 8 3 N Scale: 100 N 52 . 9768 Basic Concepts: F x,net = F x, 1 + F x, 2 F y,net = F y, 1 + F y, 2 F net = radicalBig ( F x,net ) 2 + ( F y,net ) 2 Given: F x, 1 = 1020 N F x, 2 = 480 N F y, 1 = 1285 N F y, 2 = 569 N Solution: Consider the horizontal forces: F x,net = 1020 N + ( 480 N) = 540 N Consider the vertical forces: F y,net = 1285 N + ( 569 N) = 716 N homework 04 GAUTHIER, JOSEPH Due: Sep 28 2007, 1:00 am 2 Thus the net force is F net = radicalBig (540 N) 2 + (716 N) 2 = 896 . 803 N . Question 2, chap 5, sect 1. part 2 of 2 10 points b) Find the direction of the resultant force (in relation to the 1020 N force, with up being positive). Correct answer: 52 . 9768 (tolerance 5 %). Explanation: Basic Concept: tan = F y,net F x,net Solution: = tan 1 parenleftbigg F y,net F x,net parenrightbigg = tan 1 parenleftbigg 716 N 540 N parenrightbigg = 52 . 9768 . Question 3, chap 5, sect 1. part 1 of 1 10 points Two men decide to use their cars to pull a truck stuck in mud. They attach ropes and one pulls with a force of 941 N at an angle of 30 with respect to the direction in which the truck is headed, while the other car pulls with a force of 1366 N at an angle of 23 with respect to the same direction. 9 4 1 N 3 1 3 6 6 N 2 3 What is the net forward force exerted on the truck in the direction it is headed? Correct answer: 2072 . 34 N (tolerance 1 %). Explanation: Given : F 1 = 941 N , F 2 = 1366 N , 1 = 30 , and 2 = 23 . For the first vehicle, the forward component is F 1 f = F 1 cos 1 = (941 N) cos30 = 814 . 93 N . For the second vehicle, similarly, F 2 f = F 2 cos 2 = (1366 N) cos23 = 1257 . 41 N . Thus the net forward force on the truck is F f = F 1 f + F 2 f = 814 . 93 N + 1257 . 41 N = 2072 . 34 N . Question 4, chap 5, sect 2. part 1 of 1 10 points You place a box weighing 242 . 8 N on an inclined plane that makes a 43 . 1 angle with the horizontal. Compute the component of the gravita tional force acting down the inclined plane. Correct answer: 165 . 899 N (tolerance 1 %). Explanation: Basic concepts W W W 1 homework 04 GAUTHIER, JOSEPH Due: Sep 28 2007, 1:00 am 3 The component of the gravitational force act ing down the plane is the side opposite the angle , so W 1 = W sin Question 5, chap 5, sect 3....
View
Full
Document
This note was uploaded on 03/19/2008 for the course M 408M taught by Professor Gilbert during the Fall '07 term at University of Texas at Austin.
 Fall '07
 Gilbert

Click to edit the document details