Motion in a Straight Line · Question 45

When a ruler falls vertically, 5 different persons catch it with different reaction times. (g = 9.8 ms-2) What is the correct order of the distance travelled by the ruler for each person ?

1. B > E > A > C > D
2. C > D > A > E > B
3. C > D > A > B > E
4. B > E > A > D > C

The following plots show variation of velocity (v) with time (t), of a ball thrown vertically upward, and falling back. Which of the following plots is/are correct? [figure]

1. B only
2. A and E only
3. C only
4. D only

Consider a particle moving along a straight line, whose position as a function of time is given by s(t) = t2 - t + , where = 1 m s-2, = 6 m s-1 and = 5 m. The average speed of the particle, in m s-1 from t = 0 to t = 6 s is:

1. 0
2. 12
3. 6
4. 3

In some appropriate units, time (t) and position (x) relation of a moving particle is given by t = x2 + x. The acceleration of the particle is

1. + 2(x+1)3
2. + 22x+1
3. - 2(x+2)3
4. - 2(2x+1)3

Two cities X and Y are connected by a regular bus service with a bus leaving in either direction every T min. A girl is driving scooty with a speed of 60 km/h in the direction X to Y notices that a bus goes past her every 30 minutes in the direction of her motion, and every 10 minutes in the opposite direction. Choose the correct option for the period T of the bus service and the speed (assumed constant) of the buses.

1. 10 min, 90 km/h
2. 15 min, 120 km/h
3. 9 min, 40 km/h
4. 25 min, 100 km/h

The velocity (v)- time (t) plot of the motion of a body is shown below: [figure] The acceleration (a)- time (t) graph that best suits this motion is :

1. [figure]
2. [figure]
3. [figure]
4. [figure]

A particle is moving along x-axis with its position (x) varying with time (t) as x = t4 + t2 + t + . The ratio of its initial velocity to its initial acceleration, respectively, is:

1. 2 :
2. : 2
3. 4 :
4. : 2

A vehicle travels half the distance with speed v and the remaining distance with speed 2v. Its average speed is :

1. 2v3
2. 4v3
3. 3v4
4. v3

A horizontal bridge is built across a river. A student standing on the bridge throws a small ball vertically upwards with a velocity 4 m s-1. The ball strikes the water surface after 4 s. The height of bridge above water surface is (Take g = 10 m s-2)

1. 60 m
2. 64 m
3. 68 m
4. 56 m

A bullet from a gun is fired on a rectangular wooden block with velocity u. When bullet travels 24 cm through the block along its length horizontally, velocity of bullet becomes u3. Then it further penetrates into the block in the same direction before coming to rest exactly at the other end of the block. The total length of the block is :

1. 24 cm
2. 28 cm
3. 30 cm
4. 27 cm