• Congratulations to the Class of 2024 on your results!
    Let us know how you went here
    Got a question about your uni preferences? Ask us here

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

MNfa-18

New Member
Joined
May 14, 2014
Messages
3
Gender
Male
HSC
2014
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

Well-Known Member
Joined
Feb 11, 2013
Messages
1,848
Gender
Male
HSC
2014
Soz if i'm wrong, haven't touched maths since idk ceeebs :p

 

Drongoski

Well-Known Member
Joined
Feb 22, 2009
Messages
4,255
Gender
Male
HSC
N/A
I think that answer is correct. Same as I got.


ps
I just love your crisp mathematical type. How do you do it?
 
Last edited:

photastic

Well-Known Member
Joined
Feb 11, 2013
Messages
1,848
Gender
Male
HSC
2014
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

Well-Known Member
Joined
Feb 22, 2009
Messages
4,255
Gender
Male
HSC
N/A
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.
 
Last edited:

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top