7. A solid wheel accelerates at \( 3.25 \mathrm{rad} / \mathrm{s} 2 \) when a force of 4.5 N exerts a torque on it. If the whesl is reglaced by a wheel with all of its mass on the rim, the moment of inertia is given by \( 1=m r 2 \). If the same angular velocity were desired, what force would have to be exerted on the strap?
\[
1=m r^{2} \quad \begin{aligned}
F_{N} & =2 F_{0} \\
& =2(4.5) \\
& =9 \mathrm{~N}
\end{aligned}
\]
8. A 1.5 kg signage was hung from a \( \mathrm{l}-\mathrm{kg} \), 5 -meter horizontal pole as shown. The object was hung \( 1.5- \) meter from rinht side A wire was attached to nrevent the sion from ratating. Find the tension in the wire.
