- #1
richyr33
- 9
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Homework Statement
An angular displacement θ radians in time t seconds is given by the equation θ = sin 3t. Find
a:) angular velocity when t = 1 second
b:) the smallest positive value of t for which the angular velocity is 2rad/s
c:) the angular acceleration when t = 0.5 seconds
d:) the smallest positive value of t for which the angular acceleration is 9rad/s
Homework Equations
d/dx (sin ax) = a cos ax
d/dx (cos ax) = -a sin ax
The Attempt at a Solution
Ok i have worked out parts a:) and c:)
a:) dθ/dt = 3cos 3t so when t = 1, ω = -2.97r/s
c:) dω/dt = -9sin 3t so when t = 0.5, angular acceleration = -8.98r/s/s
I can't work out parts b and d, its not a homework question i am revising from a book and the answers for parts b and d are 0.280seconds and 1.57 seconds respectively however the method is not explained. I managed to calculate the answer to part d at one point but cannot remember how i got there :shy:
Any help would be appreciated, thanks