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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.
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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
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संबंधित प्रश्न
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?
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 ?
Show the shape of the distance – time graph for the motion in the following cases.
- A bus moving with a constant speed.
- A car parked on a road side.
The slope of the distance-time graph at any point gives______.
Complete the data of the table given below with the help of the distance-time graph given in the figure.
| Distance (m) | 0 | 4 | ? | 12 | ? | 20 |
| Time (s) | 0 | 2 | 4 | ? | 8 | 10 |
Boojho goes to the football ground to play football. The distance-time graph of his journey from his home to the ground is given in the figure.
- What does the graph between points B and C indicate about the motion of Boojho?
- Is the motion between 0 to 4 minutes uniform or non-uniform?
- What is his speed between 8 and 12 minutes of his journey?
Assertion: The slope of the distance-time graph of a body moving with high speed is steeper than the slope of the distance-time graph of a body with low velocity.
Reason: Slope of distance-time graph = speed of the body.
