Q. A subway train is traveling at 83 km/h when it approaches a slower train 46m ahead traveling in the same direction at 23 km/h.If the faster train begins decelerating at 2.1 meter per second square while the slower train continues at constant speed, how soon will they collide? If the faster train begins decelerating at 2.1 meter per second square while the slower train continues at constant speed, at what relative speed will they collide?
Q. Determine the amount of work that must be done on a 100 kg payload to elevate it to a height of 1000 km above the Earth's surface. Determine the amount of additional work that is required to put the payload into circular orbit at this elevation.