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Calculus/Particle Motion

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Question
A particle moves along a so that its position at any time t(greater than or equal to) 0 is given by the function
                     s(t)= t^2- 3t + 2,
where s is measured in meters and t is measured in seconds.

(a) Find the displacement during the first 5 seconds.
(b) Find the average velocity during the first 5 seconds.
(c) Find heinstananeours velocity when t=4.
(d) Find he acceleration of the paticle when t=4.
(e) At what values of t does the particle chang direction?  

Answer
(a) Displacement=s(5)-s(0)=5^2-3*5+2-[0^2-3*0+2]=25-15=5 meters.
(b) Average velocity=Displacement/5 sec = 5/5 =1 m/s .
(c) Instananeours velocity=s'(t) at t=4 :
   s'(t)=2t-3 . s'(4)=2*4-3=3m/s .
(d) Acceleration=s''(t)=2 m/s^2 .
(e) The particle changes direction when the velocity changes sign :
   Meaning, when s'(t)=0 : 2t-3=0 --> t=1.5 sec .
   The particle is moving forward in the interval 0<t<1.5 sec
   And is moving backward in the interval 1.5<t

Alon.

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Alon Mandes

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Kind of questions I can answer : Limits, Derivatives, Integration, Implicit functions, continuousity, differentiation ,Extremum problems, Lagrange multipliers, Gradients, Surface integrals, Multi variables functions ,Multi variables Integrals,Complex variables ,Complex functions, Curves, Trajectory integrals & Vector analyse,Divergence,Rotor & word problems. Kind of question I can't answer : Economics,Combinatorics,infinite series & convergence ,Statistics & Probabilities .

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1. I'm a team member of mathnerds (math site for answering questions) 2. I'm a team member in the Student's Union of the Technion, helping students who have problems in mathematics. 3. 2 years of experience as a math teacher in college. 4. I give free homework help for high school students in Mathematics & Physics. 5. I teach part time in collage the subjects : "Digital Signal Processing" , "Random Signals & Noise" , "Complex Functions".

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M.A in Mathematics & Bs.c in Electronics.

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