I need urgent help!!!!!!!!! (1 Viewer)

MNfa-18

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Hi guys, i have a problem with this one question......

A particle moves in a straight line. At time, t seconds, its displacement Xcm from a fixed point O in the line is given by

X= 5sin((Pi/2)t
Find the speed when x=2.5


Help would be greatly appreciated :)
 

photastic

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Soz if i'm wrong, haven't touched maths since idk ceeebs :p

 

Drongoski

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I think that answer is correct. Same as I got.


ps
I just love your crisp mathematical type. How do you do it?
 
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photastic

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I think that answer is correct. Same as I got.
Would we have to consider the graph since it mentions displacement? What if the particle was travelling under the curve? Wouldn't we have to minus this?
 

Drongoski

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Would we have to consider the graph since it mentions displacement? What if the particle was travelling under the curve? Wouldn't we have to minus this?
No, you don't. But if you know the (sine) graph, maybe it'll help you understand what's going on better.

In this question, the particle is oscillating about the origin, moving to as far as x=5 to the right (of the x-axis), turn around and head for x = -5, and the to x=5, then to x = -5 ...repeatedly in what is known as a simple harmonic motion.
 
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