- #1

- 4

- 0

x(t)=5t+3sint , y(t)=(8-t)(1-cost)

Find the velocity vector at the time when the particle's horizontal position is x=25

answer is (7.008, -2.228)

*the x=25, i think the trick is somehow get the t with that..

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- Thread starter leunglik
- Start date

- #1

- 4

- 0

x(t)=5t+3sint , y(t)=(8-t)(1-cost)

Find the velocity vector at the time when the particle's horizontal position is x=25

answer is (7.008, -2.228)

*the x=25, i think the trick is somehow get the t with that..

- #2

HallsofIvy

Science Advisor

Homework Helper

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If not, you might use a "bisection" method. For example, It is obvious that X(4)= 20+ 3sin(4)< 25. It is not so obvious but easy to show with a calculator that X(7)= 28+ 3 sin(7)> 25 (but not 5 or 6). The function must be equal to 25 some place between them. Just because it is simplest, try half way between them, 5.5. X(5.5)= 25.3> 25. Now we know the function is equal to 25 some place between 4 and 5.5. Again, try half way: (4+ 5.5)/2= 4.75. X(4.75)= 20.817< 25 so now we know the solution is somewhere between 4.75 and 5.5. Half way between them is (4.75+ 5.5)/2= 5.125.

Continue unfil you feel you have sufficient accuracy.

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