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 November 28th, 2015, 01:07 AM #1 Member   Joined: Jun 2013 Posts: 42 Thanks: 0 how to find the distance given the velocity? Starting at rest, the velocity of an object is given by v = 3t^2. Find the distance traveled after 5 seconds. My solution: d =vt but v = 3t^2 so: d = (3t^2)(t) @t=5 d = [3(5)^2](5) d = [3(25)](5) d = 75(5) d = 375 units My answer is obviously correct, but the answer in the book is d=125. Please tell me whether the book is wrong or I am wrong, If I am wrong, please explain why I am wrong... thank you. Last edited by skipjack; November 28th, 2015 at 01:35 AM. November 28th, 2015, 01:47 AM #2 Global Moderator   Joined: Dec 2006 Posts: 21,019 Thanks: 2254 You are wrong. The equation d = vt applies if v is the mean velocity. In particular, this equation is correct if v is a constant. You are given that v = 3t². You need to use the fact that v is the derivative of d with respect to time. As d = 0 when t = 0, d = t³, and so d = 125 when t = 5. Tags distance, find, velocity Thread Tools Show Printable Version Email this Page Display Modes Linear Mode Switch to Hybrid Mode Switch to Threaded Mode Similar Threads Thread Thread Starter Forum Replies Last Post DerGiLLster Calculus 2 September 7th, 2015 07:04 PM Usama Farooq Geometry 2 September 7th, 2015 04:32 PM davey2015 Pre-Calculus 6 September 3rd, 2015 09:17 AM beesee Physics 1 January 7th, 2014 11:58 AM AamirAli Calculus 4 March 28th, 2013 06:40 AM

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