NCERT Physics Class 11 Exemplar Ch 3 Motion In A Straight Line Part 2

One Or More Than One Answer

Q. 7 The variation of quantity A with quantity B, plotted in Fig. describes the motion of a particle in a straight line.

(a) Quantity B may represent time.

(b) Quantity A is velocity if motion is uniform.

(c) Quantity A is displacement if motion is uniform.

(d) Quantity A is velocity if motion is uniformly accelerated.

Q. 8 A graph of x versus t is shown in Fig. Choose correct alternatives from below.

(a) The particle was released from rest at t = 0.

(b) At B, the acceleration a > 0.

(c) At C, the velocity and the acceleration vanish.

(d) Average velocity for the motion between A and D is positive.

(e) The speed at D exceeds that at E.

Q. 9 For the one-dimensional motion, described by

(a)

(b)

(c)

(d) lies between 0 and 2.

Q. 10 A spring with one end attached to a mass and the other to a rigid support is stretched and released.

(a) Magnitude of acceleration, when just released is maximum.

(b) Magnitude of acceleration, when at equilibrium position, is maximum.

(c) Speed is maximum when mass is at equilibrium position.

(d) Magnitude of displacement is always maximum whenever speed is minimum.

Q. 11 A ball is bouncing elastically with a speed 1 m/s between walls of a railway compartment of size 10 m in a direction perpendicular to walls. The train is moving at a constant velocity of 10 m/s parallel to the direction of motion of the ball. As seen from the ground,

(a) the direction of motion of the ball changes every 10 seconds.

(b) speed of ball changes every 10 seconds.

(c) average speed of ball over any 20 second interval is fixed.

(d) the acceleration of ball is the same as from the train

Q. 12 Refer to the graphs in Fig 3.1. Match the following.

Graph Characteristic

(a) (i) has v > 0 and a < 0 throughout.

(b) (ii) has x > 0 throughout and has a point with

(c) (iii) has a point with zero displacement

(d) (iv)

Answer: (a) (iii), (b) (ii), (c) iv, (d) (i)

Q. 13 A uniformly moving cricket ball is turned back by hitting it with a bat for a very short time interval. Show the variation of its acceleration with time. (Take acceleration in the backward direction as positive).