Advertisements
Advertisements
प्रश्न
The graph given alongside shows the positions of a body at different times. Calculate the speed of the body as it moves from :
(1) A to B,
(2) B to C, and
(3) C to D.
Advertisements
उत्तर
(i) The distance covered from A to B,
= 3 – 0
= 3 cm
Time taken to cover the distance from A to B
= 5 – 2
= 3 s
Hence speed,
= `"Distance"/"Time"`
= `3/3` cm/s
= 1 cm/s
(ii) The speed of the body as it moves from B to C is zero because the distance travelled is zero.
(iii) The distance covered from C to D,
= 7 – 3
= 4 cm
Time taken to cover the distance from C to D,
= 9 – 7
= 2 s
Hence speed,
= `"Distance"/"Time"`
= `4/2` cm/s
= 2 cm/s
APPEARS IN
संबंधित प्रश्न
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 distance-time graph indicates ………………….. of a moving body.
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 ?
Four cars A, B, C and D are moving on a levelled, straight road. Their distance-time graphs are shown in the given figure. Which of the following is the correct statement regarding the motion of these cars?
A spaceship is moving in space with a velocity of 60 kms−1. It fires its retro engines for 20 seconds and velocity is reduced to 55 kms−1. Calculate the distance travelled by a spaceship in 40 s, from the time of firing of the retro- rockets.
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.
The area under velocity time graph represents ______.
The slope of the distance-time graph indicates the speed.
Assertion: The position-time graph of a uniform motion in one dimension of a body can have a negative slope
Reason: When the speed of the body decreases with time then, the position-time graph of the moving body has a negative slope.
