i have been set the following question(adsbygoogle = window.adsbygoogle || []).push({});

theta = 3r^2

find the magnitude of the acceleration when

r=0.8 m

dr/dt = 4ms^-1

d^2r/dt^2 = 12 ms^-2

my working followed the process of calculating angular velocity with these conditions and angular acceleration with these conditions then plugging them into the acceleration formula for a polar coordinate system.

when doing this i get

a(radial) = -282.912 ms^-2 (componant along the radius)

a(theta) = 218.88 ms^-2 (componant perpendicular to radius)

using pythagoras to calculate the magnitude of the resultant acceleration i get a value 357.7 ms^-2

a value my dynamics lecturer is prompt to tell me is WRONG. perhaps someone can help me...PLEASE

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# Dynamics, polar coordinate system

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