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प्रश्न
The speed-time graph for a car is shown in the following figure:
- Find how far the car travels in the first 4 seconds. Shade the area on the graph that represents the distance travelled by the car during the period.
- Which part of the graph represents uniform motion of the car?
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उत्तर
The motion during the first 4 seconds is not uniformly accelerated. So, the distance travelled by car in the first 4 seconds is calculated using the graphical method.
(a) Number of squares in the shaded part of the graph is 320.5
One small square m x-axis represents `t = 2/5 s`
One small square on the y-axis represents.
`v = 2/3 ms^-1`
∴ area of each square, `v xx t`
= `2/3 xx 2/5`
= `4/15 m`
Total area = `61.5 × 4/15`
= 16.4 m
(b) The limiting flat portion of the curve describes the constant speed of the car, i.e., a speed of 6.0 m s−1. At this stage, the acceleration of the car is zero.
Therefore, a portion of the graph between t = 6 s to 10 s, describes the uniform motion of the car.
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संबंधित प्रश्न
What can you say about the motion of an object if its speed-time graph is a straight line parallel to the time axis?
Show the shape of the distance-time graph for the motion in the following case:
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Which of the following distance-time graphs shows a truck moving with speed which is not constant?
What can you say about the motion of a body whose distance-time graph is a straight line parallel to the time axis ?
Name the two quantities, the slope of whose graph give speed .
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.
Two students were asked to plot a distance-time graph for the motion described by Table A and Table B.
| Table A |
||||||
| Distance moved (m) | 0 | 10 | 20 | 30 | 40 | 50 |
| Time (minutes) | 0 | 2 | 4 | 6 | 8 | 10 |
| Table B |
||||||
| Distance moved (m) | 0 | 5 | 10 | 15 | 20 | 25 |
| Time (minutes) | 0 | 1 | 2 | 3 | 4 | 5 |
The graph given in figure is true for
If we denote speed by S, distance by D and time by T, the relationship between these quantities is ______.
What do you infer if
- Distance – time graph is a straight line.
- The velocity-time graph is curved.
- Displacement time is zigzag.
