A car is moving in the east direction with the velocity of 30.0 miles/hour. To avoid head on collision the breaks are applied and the car is brought to rest in 10.0s. Calculate the average acceleration of the car?

2 Answers

#-1.3411\ m/s^2#

Explanation:

The acceleration #a# of car moving with initial velocity #u=30\ \text{miles/hr}=13.411\ m/s# brought to rest #v=0# in time #t=10\ sec# is given as follows

#a=\frac{v-u}{t}#

#=\frac{0-13.411}{10}#

#=-1.3411\ m/s^2#

The car is experiences the retardation of #1.3411\ m/s^2#

Jul 4, 2018

Car is moving with initial velocity #u=30\ mph#
#=>u=(30xx1760xx3)/3600=44\ ft\ s#
As the car is brought to rest #v=0#
Using the kinematic expression

#v=u+at#,
where #a# is average acceleration
#=>a={v-u}/{t}#

Inserting given values

#a={0-44}/{10}#
#=>a=-4.4\ ft\ s^-2#
It is deceleration.