A 50,000 kg train is rolling on its own down the track at 5 m/s. You grab a rope trailing behind it, and exert a stopping force of 2,000N. How long does
it take to stop the train?

Aregular polygon has angkes of size 150° each.how many side has the polygon

Which type of basaltic lava flow has a fairly smooth

As you are trying to move a heavy box of mass m, you realize that it is too heavy for you to lift by yourself. there is no one around to , so you attach an ideal pulley to the box and a massless rope to the ceiling, which you wrap around the pulley. you pull up on the rope to lift the box. use g for the magnitude of the acceleration due to gravity and neglect friction forces. once you have pulled hard enough to start the box moving upward, what is the magnitude f of the upward force you must apply to the rope to start raising the box with constant velocity? express the magnitude of the force in terms of m, the mass of the box.