Force applied at a 90 degree angle to a shaft
RPM (Revolutions Per Minute) is a measurement of the frequency of rotation. It refers to the number of full rotations completed in one minute around a fixed axis. It is used as a measure of rotational speed of a mechanical component.
The rocker arm is the lever that converts the radial movement of the cams on the camshaft to the linear movement of the exhaust and inlet valves. Along with push rods and camshaft they form the mechanism that operates the valves on the cylinder head.
The rear-view mirror is a mirror in automobiles and other vehicles, designed to allow the driver to see rearward. Rear-view mirrors are usually fixed to the top center of the front windshield.