Mastering Physics: CH08 HW Google Chrome Secure l https//session.masteringphysic
ID: 1551542 • Letter: M
Question
Mastering Physics: CH08 HW Google Chrome Secure l https//session.masteringphysics.com/myct/itemView?assignmentProblemIDs 74070359 PHY-123-76-General Physics Lecture-17/SP CH08 HW Problem 8.43 Problem 8.43 The Outlaw Run roller coaster in Branson, Missouri, features a track that is inclined at 77 below the horizontal and that spans a 494 m (162 ft) change in height. Part A If the coefficient of friction for the roller coaster is puk 0.25, what is the magnitude of the friction force on a 1600-kg coaster train? Express your answer to two significant figures and include appropriate units. Value Units Submit My Answers Give Part B How much work is done by friction during the time the coaster train travels along the incline? Express your answer to two significant figures and include appropriate units. Value Units Submit My Answers Give Part C What is the speed of the coaster train at the bottom of the incline, assuming it started from rest at the top? Express your answer to two significant figures and include appropriate units. Signed in as Caitlyn Torres Resources e previous l 8 of 19 l next 7.09 PM 3/28/2017Explanation / Answer
(A) N = m g cos77
f = uk N = uk m g cos77
f = 0.25 x 1600 x 9.8 x cos77
f = 881.8 N
(B) L = 49.4 / sin77 = 50.7 m
W = - f L = - 44706.75 J
(c) Work done by gravity = m g h
= 1600 x 9.8 x 49.4
= 774592 J
Net work done = change in KE
- 44706.75 + 774592 = 1600 v^2 /2
v = 30.2 m/s