A car accelerates from 31.0m/s to rest over a displacement of 130.0m. What is the car's acceleration, and how long did it take to stop?

1 Answer
Oct 11, 2017

Answer:

#a=-3.70ms^(-2)(2dp)#

#t=8.39s(2dp)#

Explanation:

we have

#u=31ms^(-1)#

#v=0ms^(-1)#

#s=130m#

to find #a" & " t#

#color(blue)(v^2=u^2+2as)#

#0=31^2+2xxaxx130#

#0=961+260a#

#:.a=-961/260=-3.70ms^(-2)(2dp)#

#color(blue)(v=u+at)#

#0=31-3.70t#

#t=31/3.70#

#t=8.39s(2dp)#