Advertisements
Advertisements
प्रश्न
A car travels 100 km at a speed of 60 km/h and returns with a speed of 40 km/h. Calculate the average speed for the whole journey.
उत्तर
In the first case, the car travels at a speed of 60 km/h for a distance of 100 km.
Thus,
`"Time" = "Distance travelled"/"Speed"`
So , t1 = `100/60` hr
= `5/3` hr
In the second case, the car travels at a speed of 40 km/h for a distance of 100 km.
Thus,
`"Time" = "Distance travelled"/"Speed"`
So , t2 = `100/40` hr
= `5/2` hr
Total time taken :
= t1 + t2
= `5/3 + 5/2` hr
= `25/6` hr
Total distance travelled = 200 km
We can calculate average speed as:
`"Average Speed" = "Tatal Distance travelled"/"Time"`
Average speed for the entire journey :
= `"(200)(6)"/25`
= 48 km/hr
APPEARS IN
संबंधित प्रश्न
Joseph jogs from one end A to the other end B of a straight 300 m road in 2 minutes 30 seconds and then turns around and jogs 100 m back to point C in another 1 minute. What are Joseph’s average speeds and velocities in jogging?
- from A to B and
- from A to C?
Change the speed of 6 m/s into km/h.
What name is given to the speed in a specified direction ?
A tortoise moves a distance of 100 metres in 15 minutes. What is the average speed of tortoise in km/h ?
When is a body said to be in motion?
What do you mean by motion in one direction?
The diagram below shows the pattern of the oil on the road at a constant rate from a moving car. What information do you get from it about the motion of the car.
The velocity-time graph of a moving body is given below in Figure
Displacement in each part AB, BC and CD.
Distinguish between speed and velocity.
Which of the following figures (Fig. 8.3) represents uniform motion of a moving object correctly?
