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Need help with motion of particle question (1 Viewer)

kevinsta

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A projectile is fired into the air
and its height in metres is given
by h = 40t − 5t^2 + 4, where t is in
seconds.

(d) What is the maximum height
 

photastic

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Max height when dh/dt = 0. This is why at the highest point the path looks like the vertex of a parabola.
So make dh/dt = 0 and find the time it takes to reach the highest point, then subbing it back into h.
 
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Max height when dh/dt = 0. This is why at the highest point looks the path like the vertex of a parabola.
So make dh/dt = 0 and find the time it takes to reach the highest point, then subbing it back into h.
This. AND make sure you test if it is a maximum, remember a parabola could have a max or min
 
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Max height when dh/dt = 0. This is why at the highest point the path looks like the vertex of a parabola.
So make dh/dt = 0 and find the time it takes to reach the highest point, then subbing it back into h.
Yeap!

you should get 84
 

kevinsta

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Max height when dh/dt = 0. This is why at the highest point the path looks like the vertex of a parabola.
So make dh/dt = 0 and find the time it takes to reach the highest point, then subbing it back into h.
I thought when you make the velocity = 0 thats when it rests.
 

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