Question

uniform speed OI J K IT
Ans. 195 km
the two cities.
6. A car travels first 30 km with a uniform speed of
60 km h-1 and then next 30 km with a uniform speed
of 40 km h-1. Calculate : (i) the total time of journey,
(ii) the average speed of the car.
Ans. (i) 75 min, (ii) 48 km h-!.
(B) GRAPHICAL REPRESENTA
If a body moves in a straight line path, its motion
inne dimension and is called the lineare​

Answer 1

Question:

A car travels 30 Km with a uniform speed of 60 Km/h and then next 30 Km with a uniform speed of 40 Km/h. Calculate (i) the total time of the journey, (ii) the average speed of the car.

Solution:

Distance$_1$ = 30 Km

Distance$_2$ = 30 Km

Speed$_1$ = 60 Km/h

Speed$_2$ = 40 Km/h

Time$_1$ = $\frac{Distance_1}{Speed_1}$ = 30/60 = 1/2 hr × 60 min = 30 min

Time$_2$ = $\frac{Distance_2}{Speed_2}$ = 30/40 = 3/4 hr × 60 min = 45 min

∴ Total time of the journey = (30 + 45)min = 75 min.

Average speed of the car = Total distance/Total time

• (30 + 30)/(30 + 45)
• 60/1.25
• 48

∴ Average speed of the car = 48 Km/h.