Finding Force
A 5 kg box is sitting on a table. The coefficient of static friction between the box and the table is 0.4. What is the minimum horizontal force needed to move the box?
Finding Angular Velocity
Question 19
A uniform disk of mass $2 \mathrm{~kg}$ is spinning on its (vertical) axis of symmetry (remember the rotational inertia of a disk is given by $0.5 \mathrm{mr}^{2}$ ), with an angular velocity of $\mathrm{h}=5 \mathrm{rad} / \mathrm{s}$. A piece of mud if mass 1 $\mathrm{kg}$ is dropped on the disk near its edge, and the disk slows down. What is its angular velocity now? (you don't need to know the radius of the disk to solve this). $\mathrm{rad} / \mathrm{s}$
Finding Centripetal Acceleration
A rope has a maximum tension of $220 \mathrm{~N}$ before it will break. An $11 \mathrm{~kg}$ ball attached to this rope sits on a horizontal, frictionless surface and is swung around in a horizontal circle with radius $0.80 \mathrm{~m}$ at constant speed using the maximum tension. If the ball is now replaced with a heavier $33 \mathrm{~kg}$ ball and again swung around at the same constant speed and the same maximum tension, what is the radius of the $33 \mathrm{~kg}$ ball's path?
$0.80 \mathrm{~m}$
$0.27 \mathrm{~m}$
$0.89 \mathrm{~m}$
$2.4 \mathrm{~m}$