Answer:
-352.275KJ
Explanation:
We are given that
Mass of car=1500kg
Initial speed of car =u=96 km/h=[tex]96\times \frac{5}{18}=26.67m/s[/tex]
1km/h=[tex]\frac{5}{18}m/s[/tex]
Final speed of car=v=56km/h=[tex]56\times \frac{5}{18}=15.56m/s[/tex]
Distance traveled by car=s=55m
We have to find the work done by the car's braking system.
Using third equation of motion
[tex]v^2-u^2=2as[/tex]
[tex](15.56)^2-(26.67)^2=2a(55)[/tex]
[tex]-469.18=110a[/tex]
[tex]a=\frac{-469.18}{110}=-4.27m/s^2[/tex]
Where negative sign indicates that velocity of car decreases.
Work done by a car's barking system=[tex]w=F\times s=ma\times s[/tex]
Work done by a car's barking system=[tex]1500\times -4.27\times 55=352275J[/tex]
Work done by a car's barking system=[tex]-\frac{352275}{1000}=-352.275KJ[/tex]
1KJ=1000J
Where negative sign indicates that work done in opposite direction of motion.
