This preview shows pages 1–2. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: vu (tv2894) – Homework 18 (Section 4.7) – miner – (55096) 1 This printout should have 5 questions. Multiplechoice questions may continue on the next column or page – find all choices before answering. 001 10.0 points A Pine Car Derby car rolls along a track with velocity v ( t ) = 3 + 2 t t 2 feet per second. If it starts at time t = 0, after how many seconds will its position be maximized? 1. t = 9 seconds 2. none of these 3. t = 1 second 4. t = 0 seconds 5. t = 2 seconds 6. t = 3 seconds correct Explanation: Since we are maximizing the position, x ( t ), of the car, this will occur when x ′ ( t ) = 0, i.e. , when x ′ ( t ) = v ( t ) = 3 + 2 t t 2 = 0 . But 3 + 2 t t 2 = (3 t )(1 + t ) = 0 when t = 3 and when t = 1. But t = 1 is not allowed because the car starts at time t = 0. Now x ′′ ( t ) = v ′ ( t ) = 2 2 t , so x ′′ (3) = 0. Hence the position of the car will be maximized after t = 3 seconds. 002 10.0 points A rectangular dog pound with three kennels as shown in the figure consists of a rectangular fenced area divided by two partitions. Determine the maximum possible area of this pound if 40 yards of chain link fencing is available for its construction....
View
Full
Document
This note was uploaded on 11/07/2010 for the course M 408N taught by Professor Gualdini during the Fall '10 term at University of Texas.
 Fall '10
 Gualdini
 Calculus

Click to edit the document details