Advertisements
Advertisements
Question
Distance between Bholu’s and Golu’s house is 9 km. Bholu has to attend Golu’s birthday party at 7 o’clock. He started from his home at 6 o’clock on his bicycle and covered a distance of 6 km in 40 minutes. At that point, he met Chintu and he spoke to him for 5 minutes and reached Golu’s birthday party at 7 o’clock. With what speed did he cover the second part of the journey? Calculate his average speed for the entire journey.
Advertisements
Solution
Distance between Bholu’s and Golu’s house = 9 km
Distance covered by Bholu in first part of the journey = 6 km
Time taken to cover 6 km = 40 min
Distance covered by Bholu in second part of the journey = 9 − 6 = 3 km
Time taken to cover 3 km = 60 – (40 + 5) = 15 min
Speed of Bholu while covering second part of the journey
= `(3 "km")/((15/60)"h")`
= 12 km/h
Average speed of Bholu for the entire journey
= `("Total distance")/("Time taken")`
= `(9 "km")/(60 "min")`
= 9 km/h
APPEARS IN
RELATED QUESTIONS
What is the nature of the distance-time graphs for uniform and non-uniform motion of an object?
What can you say about the motion of an object whose distance-time graph is a straight line parallel to the time axis?
What can you say about the motion of an object if its speed-time graph is a straight line parallel to the time axis?
A driver of a car travelling at 52 km h−1 applies the brakes and accelerates uniformly in the opposite direction. The car stops in 5 s. Another driver going at 3 km h−1 in another car applies his brakes slowly and stops in 10 s. On the same graph paper, plot the speed versus time graphs for the two cars. Which of the two cars travelled farther after the brakes were applied?
Show the shape of the distance-time graph for the motion in the following case:
A car moving with a constant speed.
What conclusion can you draw about the speed of a body from the following distance-time graph ?
Fill in the following blank with suitable word :
The slope of a speed-time graph of a moving body gives its………………………..
A cyclist is travelling at 15 m s-1. She applies brakes so that she does not collide with a wall 18 m away. What deceleration must she have ?
A car is travelling at 20 m/s along a road. A child runs out into the road 50 m ahead and the car driver steps on the brake pedal. What must the car’s deceleration be if the car is to stop just before it reaches the child ?
A student draws a distance-time graph for a moving scooter and finds that a section of the graph is horizontal line parallel to the time axis. Which of the following conclusion is correct about this section of the graph?
