Advertisements
Advertisements
प्रश्न
A train takes 2 h to reach station B from station A, and then 3 h to return from station B to station A. The distance between the two stations is 200 km. Find:
The average speed,
The average velocity of the train.
Advertisements
उत्तर
Here, total distance = (200 + 200) km = 400 km
Total time taken = (2 + 3) h = 5 h
(i) Average speed = Total distance travelled/total time taken = `(400 "km")/(5 "h")` = 80 km h-1
(ii) Average velocity of the train is zero because the train stops at the same point from where it starts, i.e. the displacement is zero.
APPEARS IN
संबंधित प्रश्न
In addition to speed, what else should we know to predict the position of a moving body ?
State whether speed is a scalar or a vector quantity. Give reason for your choice.
Write the formula for acceleration. Give the meaning of each symbol which occurs in it.
If a bus travelling at 20 m/s is subjected to a steady deceleration of 5 m/s2, how long will it take to come to rest ?
A train travels the first 15 km at a uniform speed of 30 km/h; the next 75 km at a uniform speed of 50 km/h; and the last 10 km at a uniform speed of 20 km/h. Calculate the average speed for the entire train journey.
A car is moving along a straight road at a steady speed. It travels 150 m in 5 seconds:
How far does it travel in 6 seconds ?
Give an example of the motion of a body moving with a constant speed but with a variable velocity. Draw a diagram to represent such a motion.
A car is moving in a straight line with speed 18 km h-1. It is stopped in 5 s by applying the brakes. Find:
- the speed of car in m s-1
- the retardation and
- the speed of car after 2 s of applying the brakes.
From the displacement-time graph of a cyclist given below in the Figure, find The average velocity in the first 4 s.
