Advertisements
Advertisements
प्रश्न
A motorcyclist drives from A to B with a uniform speed of 30 km h–1 and returns back with a speed of 20 km h–1. Find its average speed.
उत्तर
Let the distance between A and B be S km.
Time taken in going from A to B = `"s"/30 "h"`
Time taken in going from B to A = `"s"/20 "h"`
Average speed of motorcyclist = `"total distance covered"/"total time taken"`
= `("S km" + "S km")/("S"/30"h" + "S"/20"h")`
= `2/(1/30 + 1/20) "km h^-1"`
= `2/(1/12) "km h"^-1`
= 24 km h−1
APPEARS IN
संबंधित प्रश्न
What does the odometer of an automobile measure?
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?
Bus X travels a distance of 360 km in 5 hours whereas bus Y travels a distance of 476 km in 7 hours. Which
bus travels faster ?
An aircraft travelling at 600 km/h accelerates steadily at 10 km/h per second. Taking the speed of sound as 1100 km/h at the aircraft’s altitude, how long will it take to reach the ‘sound barrier’ ?
A car is moving on a straight road with uniform acceleration. The speed of the car varies with time as follows :
Time (s) : 0 2 4 6 8 10
Speed (m/s) : 4 8 12 16 20 24
Draw the speed-time graph by choosing a convenient scale. From this graph :
(1) Calculate the acceleration of the car.
(2) Calculate the distance travelled by the car in 10 seconds.
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.
A car is moving with a velocity 20 m s-1. The brakes are applied to retard it at a rate of 2 m s-2. What will be the velocity after 5 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.
The velocity-time graph of a moving body is given below in Figure
Displacement in each part AB, BC and CD.
What is the relation between distance and time when the body is moving with variable velocity?
