Advertisements
Advertisements
प्रश्न
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?
उत्तर
Initial velocity u = 20 m/s.
Acceleration = 5 m/s2.
T = 2 s.
We know v= u + at.
v= 20 + 5X2= 30 m/s.
APPEARS IN
संबंधित प्रश्न
What can you say about the motion of an object whose distance-time graph is a straight line parallel to the time axis?
Given figure shows the distance-time graph of three objects A, B and C. Study the graph and answer the following questions:
- Which of the three is travelling the fastest?
- Are all three ever at the same point on the road?
- How far has C travelled when B passes A?
- How far has B travelled by the time it passes C?
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
Name the two quantities, the slope of whose graph give speed .
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 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.
What are the uses of the graphical study of motion?
Two students were asked to plot a distance-time graph for the motion described in 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 13.2 is true for
Complete the data of the table given below with the help of the distance-time graph given in Figure 13.6
Distance (m) | 0 | 4 | ? | 12 | ? | 20 |
Time (s) | 0 | 2 | 4 | ? | 8 | 10 |
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.