Q. The 2.0 kg, 20 cm diameter disk is spinning at 320 rpm. How much friction force must the brake apply to the rim to bring the disk to a halt in 2.0 s?
Q. A dentist uses a small mirror of radius 54 mm to locate a cavity in a patient's tooth. If the mirror is concave and is held 16 mm from the tooth, what is the magnification of the resulting image?