A 100kg roller coaster comes over the first hill at 2m/s the height of the first hill is 20 meters

Aknife blade is a(n) a. lever b. screw c. wedge d. inclined plane

Awhite-blue star is hotter than a red star. select the best answer from the choices provided true or false

The horizontal blue line through the middle of the lens is called the optical axis. as the lamp is moved above or below the axis, keeping the horizontal distance to the center of the lens constant, how does the horizontal distance from the lens to the image change?