farmer joe drives a tractor for 4 hours. his tractor is pulling a heavy plow across a rocky field. over the course of 4 hours, is the plow gaining or losing energy?

the first american roller coaster was the mauch chunk switchback railway, built in the mountains of pennsylvania in the mid-1800s. the track, originally built to send coal to a railway, was reconfigured as a "scenic tour."

high-sugar diet and high cholesterol