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.
Answer:
The focal length of the appropriate corrective lens is 35.71 cm.
The power of the appropriate corrective lens is 0.028 D.
Explanation:
The expression for the lens formula is as follows;

Here, f is the focal length, u is the object distance and v is the image distance.
It is given in the problem that the given lens is corrective lens. Then, it will form an upright and virtual image at the near point of person's eye. The near point of a person's eye is 71.4 cm. To see objects clearly at a distance of 24.0 cm, the corrective lens is used.
Put v= -71.4 cm and u= 24.0 cm in the above expression.


f= 35.71 cm
Therefore, the focal length of the corrective lens is 35.71 cm.
The expression for the power of the lens is as follows;

Here, p is the power of the lens.
Put f= 35.71 cm.

p=0.028 D
Therefore, the power of the corrective lens is 0.028 D.
The speed of sound at sea level is 340.29 m/s (meters per seconds).