Increase or decrease? 35 points ??? Please help

How much force must a locomotive exert on a 12840-kg boxcar to make it accelerate forward at 0.490 m/s2?

15. one purpose of the tread pattern on a tire is to a reduce tire wear. b. reduce traction c. allow water to flow away from the tire. d. look impressive.

In a stagnant pool of water, a crayfish may spend much of its time lying with one side of its carapace near the surface of the water. in this position, it will move the walking legs on that side in a rhythmic back-and-forth motion. explain the likely function of this behavior.