A worker pushes a crate up a ramp Which change to the ramp would be the best way to increase its mechanical
efficiency (ME), and why?
O A. Reduce the length of the ramp so that more work is done in less
time.
O B. Wax the sloped surface of the ramp to decrease the friction
between the crate and the ramp.
O c. Cover the ramp with sandpaper to increase the friction between
the crate and the ramp.
O D. Reduce the height of the ramp so that less output work is done on
the crate.