Advertisements
Advertisements
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?
Advertisements
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.
संबंधित प्रश्न
Show the shape of the distance-time graph for the motion in the following case:
A car moving with a constant speed.
Figure shows the distance-time graph for the motion of two vehicles A and B. Which one of them is moving faster?
Figure: Distance-time graph for the motion of two cars
Which of the following distance-time graphs shows a truck moving with speed which is not constant?
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 ?
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.
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 body moves along a straight road with a speed of 20 m/s and has a uniform acceleration of 5 m/s2. What will be its speed after 2 s?
Starting from A, Paheli moves along a rectangular path ABCD as shown in figure. She takes 2 minutes to travel each side. Plot a distance-time graph and explain whether the motion is uniform or non-uniform.
The slope of the distance-time graph indicates the speed.
What do you infer if
- Distance – time graph is a straight line.
- The velocity-time graph is curved.
- Displacement time is zigzag.
