A car accelerates from #32.0m/s# to rest with an acceleration of #-3.20m/s^2#. What is the car's displacement from t=2 to t=3 seconds? What is the car's displacement from t=4 to t=5 seconds?

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Answer 1 · 2017-10-30T09:58:02

#A)24m#
#B)17.6m#

1. From #t=2# to #t=3# ,

First, we'll find the velocity at time 2s.

#v=u+at#
#=32m/s+(-3.2)m/s^2 *2s#
#=25.6m/s#

Now, we'll substitute that in the displacement equation, with time being 1s (the time between #t=2# to #t=3#)

#S=ut+0.5at^2#
#=25.6m/cancels*1cancels+0.5*(-3.2)m/cancels^2*(1cancels)^2#
#=24m#

#----------#

2. From #t=4# to #t=5# ,

We'll follow the same method.

#v=u+at->" speed at "4 s#
#=32+(-3.2)4#
#=19.2m/s#

#S=ut+0.5at^2#
#=19.2*1+0.5*(-3.2)*1^2#
#=17.6m#