The average speed of the car is 93.33 km/hr and the average velocity of the car is 40 km/hr.
The total distance cover in east direction is=100*3=300 km
The total distance cover in the west direction=80*1.5=120 km
The total distance covered is =300+120=420 km
And Total displacement of the car is =300-120=180 km
As we know that the average speed is given as
Avg Speed =Total Distance / Total time
=420/4.5=93.33 km/hr
As we know that the average velocity is given as
Avg Speed =Total Displacement/ Total time
=180/4.5=40 km/hr
Therefore, The average speed of the car is 93.33 km/hr and the average velocity of the car is 40 km/hr.
We know that the Delta E + W(Work done by non-conservative
forces) = 0 (change of energy)
In here, the non-conservative force is the friction force
where f = uN (u =kinetic friction coefficient)
W= f x d = uNd ; N=mg
Delta E = 1/2 mV^2 -1/2mVi^2
umgd + 1/2mV^2 - 1/2mVi^2 = 0 (cancel out the m term)
This will then give us:
1/2Vi^2-ugd = 1/2V^2
V^2 = Vi^2 - 2ugd
So plugging in our values, will give us:
V= Sqrt (5.6^2 -2.3^2)
=sqrt (26.07)
= 5.11 m/s
I think it is C. I hope I helped.
