Position Time Graph

Q. Look at the graphs (a) to (d) (Fig. 3.20) carefully and state, with reasons, which of these cannot possibly represent one-dimensional motion of a particle.

Q. Suggest a suitable physical situation for each of the following graphs (Fig 3.22):

Q. From the following displacement-time graph find out the velocity of a moving body

1. $\frac{1}{\sqrt{3}}m/s$
2. $3m/s$
3. $\sqrt{3}m/s$
4. $\frac{1}{3}$

Q. Figure 3.21 shows the x-t plot of one-dimensional motion of a particle. Is it correct to say from the graph that the particle moves in a straight line for t < 0 and on a parabolic path for t >0 ? If not, suggest a suitable physical context for this graph.

Q. Two stones are thrown up simultaneously from the edge of a cliff 200 m high with initial speeds of 15 m s¯¹ and 30 m s¯¹. Verify that the graph shown in Fig. 3.27 correctly represents the time variation of the relative position of the second stone with respect to the first. Neglect air resistance and assume that the stones do not rebound after hitting the ground. Take g = 10 m s¯². Give the equations for the linear and curved parts of the plot.

Q. A drunkard walking in a narrow lane takes 5 steps forward and 3 steps backward, followed again by 5 steps forward and 3 steps backward, and so on. Each step is 1 m long and requires 1 s. Plot the x-t graph of his motion. Determine graphically and otherwise how long the drunkard takes to fall in a pit 13 m away from the start.

Q.

What is the total distance travelled till 30 seconds?

1. 30 m

2. 40 m

3. -10 m

4. 10 m

Q. A mosquito net over a 7 ft × 4 ft bed is 3 ft high. The net has a hole at one corner of the bed through which a mosquito enters the net. It flies and sits at the diagonally opposite upper corner of the net. (a) Find the magnitude of the displacement of the mosquito. (b) Taking the hole as the origin, the length of the bed as the X-axis, it width as the Y-axis, and vertically up as the Z-axis, write the components of the displacement vector.

Q. The graph of displacement v/s time is


Its corresponding velocity-time graph will be

1. 
2. 
3. 
4. 

Q. Figure 3.24 gives the x-t plot of a particle in one-dimensional motion. Three different equal intervals of time are shown. In which interval is the average speed greatest, and in which is it the least ? Give the sign of average velocity for each interval.

Q.

When does the body come back to its starting point?

1. 5 sec

2. 10 sec

3. 30 sec

4. 20 sec

Q.

What is the distance of the body from the starting point at t = 30 s?

What is the distance of the body from the starting point at t = 30 s?

1. 10 m

2. 20 m

3. -10 m

4. 0 m

Q.

Figure 3.24 gives the x-t plot of a particle in one-dimensional motion. Three different equal intervals of time are shown. In which interval is the average speed greatest, and in which is it the least? Give the sign of average velocity for each interval.

(Fig: 3.24)

Q. X-Y plot of a body undergoing motion in 2 dimensions is a photograph of the actual motion.

1. False
2. True

Q. A player hits a ball towards a net of height 5 m with a speed of 20m/s. The ball just rises up to the top of the net and falls inside it. Find the horizontal distance this Ball would have travelled had there been no net in its way. (Take g=10m/s^2)​

Q. Figure (3-E4) shows the graph of the x-coordinate of a particle going along the X-axis as a function of time. Find (a) the average velocity during 0 to 10 s, (b) instantaneous velocity at 2, 5, 9 and 12s.

Figure

Q.

When is the object at rest?

1. t = 5 sec

2. t = 10 sec

3. t = 20 sec

4. t = 30 sec

Q. To represent motion in 2 dimensions, graphically varying with time, we need at least 3 axes.

1. False
2. True

Q.

Figure 5.17 shows the position-time graph of a body of mass 0.04 kg. Suggest a suitable physical context for this motion. What is the time between two consecutive impulses received by the body? What is the magnitude of each impulse?

Figure 5.17

Q. What is the average velocity during time interval $t=2\text{s}$ to $t=5\text{s}$, in the following position time curve?

1. $2\text{m/s}$
2. $\frac{2}{3}\text{m/s}$
3. $1.2\text{m/s}$
4. $0.4\text{m/s}$

Q. The average velocity of the object over the time interval ($2s$ to $4s$) will be (here $x$ is the position of the object)

1. $4\text{m/s}$
2. $2\text{m/s}$
3. $8\text{m/s}$
4. $6\text{m/s}$

Q.

The displacement-time graph for two particles A and B are straight lines inclined at angles of ${30}^{\circ }$ and ${60}^{\circ }$ with the time axis. The ratio of velocities of $V_A$ : $V_B$ is

1. 1:2

2. 

3. 

4. 1:3

Q.

Figure 3.21 shows the x-t plot of one-dimensional motion of a particle. Is it correct to say from the graph that the particle moves in a straight line for t < 0 and on a parabolic path for t > 0? If not, suggest a suitable physical context for this graph.

(Fig 3.21)

Q. Compare the speed of the three particles $A,B$ and $C$ as per the distance-time graph shown below.

1. $v_A>v_B>v_C$
2. $v_A>v_C>v_B$
3. $v_B>v_A>v_C$
4. $v_C>v_A>v_B$

Q. 18.An object is given at initial velocity of 25/4 m/s and then it is decelerated at a rate given by dv/dt=-5/2v in si units. the time taken by paricle to come to rest is

Q. Which of the following represents an impossible situation?

1. 
2. 
3. 
4.