## Engineering Mechanics: Statics & Dynamics (14th Edition)

$v_A=2.6m/s$, $a_A=9.35m/s^2$
We can determine the required velocity and acceleration as follows: $v_A=\omega r$ $\implies v_A=(5t^2+2)r$ We plug in the known values to obtain: $v_A=[5(0.5)^2+2](0.8)$ This simplifies to: $v_A=2.6m/s$ We know that $a_z=ar=(10t)r=10(0.5)(0.8)=4m/s^2$ and $a_n=(5t^2+2)^2r=[5(0.5)^2+2]^2(0.8)=8.45m/s^2$ Now, $a_A=\sqrt{a_z^2+a_n^2}$ We plug in the known values to obtain: $a_A=\sqrt{(4)^2+(8.45)^2}$ This simplifies to: $a_A=9.35m/s^2$