A car starting from rest speeds up to 40 ft/s with a constant acceleration of 4 ft/s^2, runs at this speed for a time, and finally comes to rest with a deceleration of 5 ft/s^2. If the total distance traveled is 1000 ft, find the total time required. Determine also the average speed for the entire trip.

Question

ghazi · Answer

|dw:1345123417331:dw| lets divide the journey in two parts....for part one use 
$$v=u+a*t...v=40+4*t1$$ now in the second part final velocity = 0 so use $$V=U-a*t.....U=a*t....U=5*t2$$..

ghazi · Answer

now U=v..as the final velocity of first part = initial velocity of second

anonymous · Answer

$$V _{0}=0 ft/s^2 $$ ? @ghazi

ghazi · Answer

yes in the second part final velocity V=0

anonymous · Answer

okay thanks~~! :)