Answer:
Change 45 min to .75 hrs
Distance = speed * time
Train A's distance = 55(t+.75)
Train B's distance = 70t
The equation
D(t) = 70t + 55(t+.75)
I believe it might be 107.9 after if that’s what your asking-like taking off 10% of $108.
B=(32)(1700) your answer should be 54,400 BTU's
24ft/s for the 1st second then it'd be 9.8mp/s which is the speed of velocity towards earth, so the 24ft/s - the 9.8 would be 14.2ft/s which is the second, the third would then be 4.4 after again subtracting 9.8. That is as far as I got, hope that helps even slightly