Graphical understanding of derivatives, Mathematics

Graphical Understanding of Derivatives:

A ladder 26 feet long is leaning against a wall. The ladder begins to move such that the bottom end moves away from the wall at a constant velocity of 2 feet by per second.   What is the downward velocity of the top end of the ladder when the bottom end is 10 feet from the wall?


Begin with the Pythagorean Theorem for a right triangle:     a2 = c2 - b2

Obtain the derivative of both sides of this equation with respect to time t.  The c, representing the length of the ladder is a constant.

2a(da/dt) = -2b(db/dt)

a(da/dt) = -b (db/dt)

But, db/dt is the velocity at that the bottom end of the ladder is moving  away  from  the  wall,  equal  to  2  ft/s,  and  da/dt  is  the downward  velocity  of the top end of the ladder  along  the wall, that is the quantity  to be determined.  Set b equal to 10 feet, substitute the known values into the equation, and solve for a.

a2 = c2 - b2


2442_Graphical Understanding of Derivatives.png

a= 24 ft

a(da/dt) = -b (db/dt)

(da/dt) = -b/a (db/dt)

(da/dt) = -10 ft/24 ft(2 ft/s)

(da/dt) = -0.833 ft/s

Therefore, when the bottom of the ladder is 10 feet from the wall and moving at 2ft/sec., the top of the ladder is moving downward at 0.833 ft/s. (The negative sign denotes the downward direction.)

Posted Date: 2/11/2013 1:04:24 AM | Location : United States

Related Discussions:- Graphical understanding of derivatives, Assignment Help, Ask Question on Graphical understanding of derivatives, Get Answer, Expert's Help, Graphical understanding of derivatives Discussions

Write discussion on Graphical understanding of derivatives
Your posts are moderated
Related Questions
Pepsi:               A dummy variable where 1 denotes choice of Pepsi by the i-th customer and 0 otherwise Price_P:           The price of a 2-liter bottle of Pepsi at the time

The Cartesian product (also called as the cross product) of two sets A and B, shown by AΧB (in the similar order) is the set of all ordered pairs (x, y) such that x€A and y€B. What

Determine the property of Partial ordered relation Question: Partial ordered relation is transitive, reflexive and  Answer: antisymmetric

Simplify following and write the answers with only positive exponents.  (a) ( x 8.2 y -0.26 z 2 ) 0.5  (b)  (x 3 y -4.1   / x -2.7 ) -3 Solution  (a) (x 8.2

can you help me? cause im in 7th grade advanced math and tomorrow I have a test tomorrow and I don''t get this

what is the remainder when 75 is divided by 4

In order to compute the inequalities of the form   where n 1 , n 2 , ....... , n k , m 1 , m 2 , ....... , m p are natural and real numbers and a 1 , a 2 , ... , a k ,

can you help me with math

The Definition- The definition of the Laplace transforms. We will also calculate a couple Laplace transforms by using the definition. Laplace Transforms- As the earlier secti