A high-speed bullet train accelerates and decelerates at the rate of 4 ft/s2. Its maximum cruising speed is 90 mi/h. (Round your answers to three decimal places.)

Question

(a) What is the maximum distance the train can travel if it accelerates from rest until it reaches its cruising speed and then runs at that speed for 15 minutes?


(b) Suppose that the train starts from rest and must come to a complete stop in 15 minutes. What is the maximum distance it can travel under these conditions?


(c) Find the minimum time that the train takes to travel between two consecutive stations that are 45 miles apart.


(d) The trip from one station to the next takes at minimum 37.5 minutes. How far apart are the stations?

Answer 1

90 mi/hr = 132 ft/s

(a) first how long and how far to reach 132 ft/s
v = 0 + 4 t
132 = 4 t
t = 33 s to reach 132
d = .5 a t^2 = 2 (33)^2 = 2178 ft to reach cruising speed
15*60 = 900 seconds total
900 - 33 = 867 seconds left
how far at cruising speed
132 ft/s * 867 s = 114,444ft
total distance = 114,444 + 2178
= 116,622 ft
= 22 miles

Answer 2

b) the answer is in (a)
twice 2178 feet

I think you can figure the rest out

Answer 3

I did put these answers in but they're marked wrong

Thank you!

Answer 4

What is a solid figure?

Answer 5

Bcz it is wrong lol