CBSE Questions for Class 9 Physics Motion Quiz 3 - MCQExams.com

The graph above shows the position versus time for three different cars 1,2, andRank these cars according to the magnitudes of their velocities, greatest first.
492253_3cc024218736451ab272988308887741.png
  • 1, 2, 3
  • 3, 2, 1
  • 2, 1, 3
  • 2, 3, 1
  • all tie
A ball of mass $$m$$ is thrown straight upward from the top of a multi-storey building with an initial velocity of $$15 \ m/s$$.
Find out the time taken by the ball to reach its maximum height?
  • $$25 \ s$$
  • $$15 \ s$$
  • $$10 \ s$$
  • $$5 \ s$$
  • $$1.5 \ s$$
A car accelerates from rest at a rate of $$4 m/s^2$$ for $$10 \ s$$. Calculate the speed of the car at the end of $$10 \ s$$?
[Unless otherwise stated, use $$g=10m/s^2$$ and neglect air resistance ]
  • 14 m/s
  • 6 m/s
  • 2.5 m/s
  • 0.4 m/s
  • 40 m/s
The above graph shows position as a function of time for an object moving along a straight line. During which time(s) is the object at rest?
I. $$0.5$$ seconds
II. From $$1$$ to $$2$$ seconds
III. $$2.5$$ seconds
494624_8e9058e0ce814332bd280363d742c461.png
  • I only
  • II only
  • III only
  • I and III only
Match the entries in Column-I with those in Column-II.
Column - IColumn - II
aSpeed1cm
bAcceleration2s
cDisplacement3$$m s^{-1}$$
dTime4$$km h^{-2}$$
  • a-2, b-1, c-4, d-3
  • a-3, b-4, c-1, d-2
  • a-4, b-2, c-3, d-1
  • a-3, b-2, c-2, d-1
A football player initially at rest starts 20 meters from the goal line. He accelerates towards the goal line at 2m/s$$^2$$. Find out the distance between player and goal line after 4s?
  • 8 m
  • 28 m
  • 32 m
  • 4 m
  • 52 m
In a uniform circular motion, the magnitude and direction of velocity at different points remain the same.
  • True
  • False
The accelerated motion of a body changes due to change in:
  • Speed
  • Direction of motion.
  • Velocity.
  • All of the above
Uniform circular motion is called continuously accelerated motion mainly because its :
  • direction of motion changes
  • speed remains the same
  • velocity remains the same
  • direction of motion does not change
A particle is pushed along a horizontal surface in such a way that it starts with a velocity of 12 m $$s^{-1}$$, and decreases at the rate of 0.5 m $$s^{-2}$$. Find the time it will take to come to rest.
  • 6 s
  • 12 s
  • 24 s
  • 48 s
A ball is thrown vertically upward with a speed of $$25.0\ m/s$$. How high does it rise?
  • $$31.9 m$$
  • $$32 m$$
  • $$33 m$$
  • $$33.9$$
A truck and a car are moving with equal velocity. On applying brakes, if both decelerate at the same rate,what happens?
  • The truck will cover less distance before stopping.
  • The car will cover less distance before stopping.
  • Both will cover equal distance.
  • None of the above
A car starts from rest and accelerates uniformly over a time of $$5.21$$ seconds for a distance of $$110$$ m. Determine the acceleration of the car.
  • $$8.10 m/s/s$$
  • $$8.1 m/s/s$$
  • $$8.0 m/s/s$$
  • $$7.10 m/s/s$$
Choose the correct option.
Odometer: Distance :: ______:______
  • Weighing scale : Weight
  • Length : Width
  • Inch : Foot
  • Mileage : Speed
In circular motion, the
  • Direction of motion is fixed
  • Direction of motion changes continuously
  • Acceleration is zero
  • Velocity is constant
In a uniform linear motion which of the following quantities remains zero?
  • Speed
  • Velocity
  • Acceleration
  • None of these
An uniform circular motion is an uniform velocity motion
  • True
  • False
Speed can be defined as :
  • $$\dfrac{Distance }{time}$$ 
  • $$\dfrac{Distance }{{Time}^2}$$ 
  • $$\dfrac{Time}{Distance}$$ 
  • $$None\  of\  the\  above$$ 
If a particle moves in a closed path with a constant speed of 10 m/s, we can always say, that there will be a change in velocity. 
  • True
  • False
The velocity of a body moving with a uniform acceleration of $$2 m/sec^2$$ is $$ 10 m/sec$$. Its velocity after an interval of 4 sec is 
  • 12 m/sec
  • 14 m/sec
  • 16 m/sec
  • 18 m/sec
The rate of change of velocity is:
  • Force
  • Momentum
  • Acceleration
  • Displacement
A body moving along a straight line at 20 metre per second undergoes an acceleration of 4 metre per second square. After 2 second it speed will be:
  • 12 metre per second
  • 28 metre per second
  • 72 metre per second
  • 20 metre per second
Ball A is dropped freely while another ball B is thrown vertically downward with an initial velocity $$v$$ from the same point simultaneously. After $$t\ seconds$$ they are separated by a distance of: (Given that $$t$$ is less than the time required by ball B to reach the ground.) 
  • $$\dfrac{vt}{2}$$
  • $$\dfrac{1}{2}gt^{2}$$
  • $$vt$$
  • $$vt+\dfrac{1}{2}gt^{2}$$
A body starting with a velocity $$v$$ returns to its initial position after $$t$$ second with the same speed along the same line. Acceleration of the particle is :
  • $$\dfrac{-2v}{t}$$
  • $$\dfrac{2v}{t}$$
  • $$\dfrac{v}{2t}$$
  • $$\dfrac{t}{2v}$$
A body dropped from the top of a tower reaches the ground in $$4\;s$$. Height of the tower is (Take $$g=9.8 \ m/s^2$$):
  • $$39.2\ m$$
  • $$44.1\ m$$
  • $$58.8\ m$$
  • $$78.4\ m$$
If the positive direction is downward, which situation involves negative velocity and zero acceleration?
  • A rocket slowing down as it moves upward
  • A rocket moving downward at a constant speed
  • A rocket moving upward at a constant speed
  • A rocket speeding up as it moves upward
The displacement - time graphs of two bodies A and B are OP and OQ respectively. If $$\angle $$POX is $$60^{0}$$ and $$\angle $$QOX is $$45^{0}$$, the ratio of the velocity of A to that of B is

69.jpg
  • $$\sqrt{3}:\sqrt{2}$$
  • $$\sqrt{3}:1$$
  • $$1: \sqrt{3}$$
  • $$3:1$$
A body falls freely from rest. If at an instant, the velocity acquired is numerically equal to the displacement, then the velocity acquired is:
  • $$9.8\ m/s$$
  • $$19.6\ m/s$$
  • $$29.4\ m/s$$
  • $$39.2\ m/s$$
The figure shows four graphs of displacement ($$x$$) versus time ($$t$$), the graph that shows a constant, positive, and non-zero velocity is:
2143.png
  • $$(a)$$
  • $$(b)$$
  • $$(c)$$
  • $$(d)$$
A lift is coming from 8th floor and is just about to reach 4th floor. Taking ground floor as origin and positive direction upwards for all quantities, which one of the following is correct?
  • x < 0, v < 0, a > 0
  • x > 0, v < 0, a < 0
  • x > 0, v < 0, a > 0
  • x > 0, v > 0, a < 0
If north is the positive direction, which situation involves positive velocity and negative acceleration?
  • A car speeding up as it moves southward
  • A car moving southward at a constant speed
  • A car slowing down as it moves northward
  • A car slowing down as it moves southward
The distances travelled by a body starting from rest and travelling with uniform acceleration in successive intervals of time each of one second will be in the ratio:
  • $$1:2:3$$
  • $$1:2:4$$
  • $$1:3:5$$
  • $$1:5:9$$
A body reaches the ground in $$3\;s$$ when it is released with zero velocity from the top of a building. The height of the building is:
  • $$14.7\ m$$ 
  • $$24.4\ m$$
  • $$44.1\ m$$
  • $$66.2\ m$$ 
The displacement time graph of a moving particle is shown in the figure. The instantaneous velocity of the particle is negative at the point:

2328.jpg
  • D
  • F
  • C
  • E
A balloon starts from rest, moves vertically upwards with an acceleration $$\dfrac{g}{8}\ \text{ms}^{-2}$$. A stone falls from the balloon after $$8\ \text{s}$$ from the start. The time taken by the stone to reach the ground  is $$\left(g=9.8\ \text{ms}^{-2}\right)$$:
  • $$4\; s$$
  • $$8\; s$$
  • $$2$$$$\sqrt{2}$$ s
  • $$12\; s$$
A pebble is thrown vertically upwards from a bridge with an initial velocity of $$4.9 \;ms^{-1}$$. It strikes the water after $$2\;s$$. Height of the bridge is:
  • $$19.6$$ m
  • $$14.7$$ m
  • $$9.8$$ m
  • $$4.9$$ m
A body thrown vertically upwards reaches the highest point in $$2\;s$$. Initial velocity of projection is_____
  • 9.8 $$ms^{-1}$$
  • 19.6 $$ms^{-1}$$
  • 29.4 $$ms^{-1}$$
  • 39.2 $$ms^{-1}$$
A body thrown up with some initial velocity reaches a maximum height of $$50\;m$$. Another body with double the mass thrown up with double the initial velocity will reach a maximum height of :
  • $$100$$ m
  • $$200$$ m
  • $$400$$ m
  • $$50$$ m
A body projected up with a velocity $$u$$ reaches maximum height $$h$$. To reach double the height, it must be projected up with a velocity of:
  • $$2u$$
  • $$\dfrac{u}{2}$$
  • $$\sqrt{2}u$$
  • $$\dfrac{u}{\sqrt{2}}$$
A ball dropped freely takes $$0.2\;s$$ to travel the last $$6\;m$$ distance before hitting the ground. Total time of fall is $$(g=10\;ms^{-2})$$:
  • $$2.9\ s$$
  • $$3.1\ s$$
  • $$2.7\ s$$
  • $$0.2\ s$$
The average velocity of a body moving with uniform acceleration after travelling a distance of $$3.06\ m$$ is $$0.34\ {m/s}$$. The change in velocity of the body is $$0.18\ {m/s}$$. During this time, its acceleration is
  • $$0.01\ {m/s}^{2}$$
  • $$0.02\ {m/s}^{2}$$
  • $$0.03\ {m/s}^{2}$$
  • $$0.04\ {m/s}^{2}$$
Two bodies are projected simultaneously with the same speed of $$19.6 \;ms^{-1}$$ from the top of a tower, one vertically upwards and the other vertically downwards. As they reach the ground, the time gap is:
  • 0 s
  • 2 s
  • 4 s
  • 6 s
Two balls are dropped to the ground from different heights. One ball is dropped $$2\ s$$ after the other but both of them strike the ground simultaneously $$5\ s$$ after the first is dropped. The difference in the heights, when they are dropped is ($$g=10\  m/s^2$$)
  • 80 m
  • 45 m
  • 95 m
  • 100 m
A body released from a height falls freely towards the earth. Another body is released from the same height exactly a second later. Then the separation between the two bodies two seconds after the release of the second body is
  • 4.9 m
  • 9.8 m
  • 19.6 m
  • 24.5 m
A body is thrown vertically upwards and rises to a height of 10 m. The velocity with which the body was thrown upwards is($$g=9.8\ m/s^2$$)
  • 16 m/s
  • 15 m/s
  • 14 m/s
  • 12 m/s
A stone is dropped from a balloon at an altitude of $$280\ m$$. If the balloon ascends with a velocity of $$5\ ms^{-1}$$ and descends with a velocity of $$5\ ms^{-1}$$, times taken by the stone to reach the ground in the two cases respectively are ($$g=10\ ms^{-2}$$):
  • $$8\ s$$ and $$9\ s$$
  • $$9\ s$$ and $$8\ s$$
  • $$3\ s$$ and $$4\ s$$
  • $$8\ s$$ and $$7\ s$$
A parachutist after bailing out falls 50 m without friction. When parachute opens, it decelerates at  $$2\ m/ s^{2}$$ . He reaches the ground with a speed of $$ 3\ m/ s$$ .  At what height, did he bail out ? (Given $$g=9.8\ m/s^2$$ approximately)
  • 91 m
  • 182 m
  • 293 m
  • 111 m
A body is thrown vertically up with certain velocity. If $$h$$ is the maximum height reached by it, its position when its velocity reduces to $$(1/3)^{rd}$$ of its velocity of projection is at
  • 8h/9 from the ground
  • 8h/9 below the top-most point
  • 4h/9 from the ground
  • h/3 below the top-most point
A ball is dropped from the top of a building. The ball takes $$0.5$$ s to fall past the window $$3$$ m in length at certain distance from the top of the building.  ($$g=10\;ms^{-2}$$)
Speed of the ball as it crosses the top edge of the window is 
  • $$3.5 \;ms^{-1}$$
  • $$8.5 \;ms^{-1}$$
  • $$5 \;ms^{-1}$$
  • $$12\; ms^{-1}$$
A person standing on the edge of a well throws a stone vertically upwards with an initial velocity $$5ms^{-1}$$. The stone goes up, comes down and falls in the well making a sound. If the person hears the sound 3 second after throwing, then the depth of water is (neglect time travel for the sound and take $$g = 10ms^{-2}$$):
  • $$1.25$$ m
  • $$21.25$$ m
  • $$30$$ m
  • $$32.5$$ m
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