CBSE Questions for Class 9 Physics Motion Quiz 6 - MCQExams.com

If you were to throw a ball vertically upward with an initial velocity of $$50 \; ms^{-1}$$, approximately how long would it take for the ball to return to your hand? Assume air resistance is negligible. (Given $$g=10\; ms^{-2}$$)
  • $$2.5 \;s$$
  • $$5.0 \;s$$
  • $$7.5 \;s$$
  • $$10 \;s$$
A stone thrown upward with a speed $$u$$ from the top of the tower reaches the ground with a velocity $$3u$$. The height of the tower is
  • $$3 { { u }^{ 2 } }/{ g }$$
  • $$4 { { u }^{ 2 } }/{ g }$$
  • $$6 { { u }^{ 2 } }/{ g }$$
  • $$9 { { u }^{ 2 } }/{ g }$$
If a particle moves in a circle with constant speed, its velocity :
  • remains constant
  • changes in magnitude
  • changes direction
  • changes both in magnitude and directions
A rubber ball is dropped from a height of $$5  m$$ on a planet where the acceleration due to gravity is same as that on the surface of the earth. On bouncing, it rises to a height of $$1.8  m$$. the ball loses its velocity by a factor of
  • $$\displaystyle\frac { 3 }{ 5 }$$
  • $$\displaystyle\frac { 9 }{ 25 }$$
  • $$\displaystyle\frac { 2 }{ 5 }$$
  • $$\displaystyle\frac { 16 }{ 25 }$$
A steel ball is bouncing up and down on a steel plate with a period of oscillation 1 second. If $$g=10  { m }{ { s }^{-2 } }$$, then it bounces up to a height of
  • $$5$$ $$m$$
  • $$10$$ $$m$$
  • $$2.5$$ $$m$$
  • $$1.25$$ $$m$$
A body is projected vertically upward with an initial velocity $$u$$. If acceleration due to gravity is $$g$$, the time for which it remains in air, is
  • $$\displaystyle\frac{u}{g}$$
  • $$ug$$
  • $$\displaystyle\frac{2u}{g}$$
  • $$\displaystyle\frac{u}{2g}$$
A pebble is thrown vertically upwards with a speed of $$20\ ms^{-1}$$. How high will it be after $$2\ s$$? (Take $$g=10\ ms^{-2}$$)
  • 40 m
  • 10 m
  • 20 m
  • 25 m
A body falls from the top of a building and reaches the ground $$2.5  s$$ later. How high is the building? (Take $$g=10  m  {s}^{-2}$$)
  • 30.6 m
  • 31.25 m
  • 30 m
  • 25 m
Statement 1:Two balls of different masses are thrown vertically upward with same speed.They will pass through their point of projection in downward direction with the same speed.
Statement 2:The maximum height and downward velocity attained at the point of projection are independent of the mass of the ball
  • Statement -1 is false , Statement- 2 is true.
  • Statement-1 is true, Statement-2 is true , Statement-2 is a correct explanation for statement-1
  • Statement-1 is true , Statement-2 is true; Statement-2 is not a correct explanation for statement-1
  • Statement -1 is true, Statement-2 is false.
A pebble thrown vertically upwards with an initial velocity $$50 \ m s^{-1}$$ comes to a stop in 5 s. Find the retardation assuming displacement in upwards direction to be positive.
  • $$-10 \ m s^{-2}$$
  • $$10 \ m s^{-2}$$
  • $$250  \ m s^{-2}$$
  • $$-250 \ m s^{-2}$$
The velocity of an object increases at a constant rate from $$20 m s^{-1}$$ to $$50 m s^{-1}$$in 10 s. Find the acceleration.
  • $$-3 \,m \,s^{-2}$$
  • $$-30 \,m \,s^{-2}$$
  • $$30 \,m \,s^{-2}$$
  • $$3 \,m \,s^{-2}$$
A stone is dropped freely from the top of a tower and it reaches the ground in $$4\ s$$. Taking $$g=10\ ms^{-2}$$, calculate the height of the tower.
  • 80 m
  • 40 m
  • 4 m
  • 20 m
A truck of mass $$5\times 10^3\ kg$$ starting from rest travels a distance of $$0.5\ km$$ in $$10\ s$$ when a force is applied on it. Calculate the acceleration acquired by the truck
  • $$25ms^{-2}$$
  • $$1ms^{-2}$$
  • $$10cms^{-2}$$
  • $$10ms^{-2}$$
An object falling freely from rest reaches ground in $$2  s$$. If acceleration due to gravity is $$9.8  ms^{-2}$$, the velocity of object on reaching the ground will be
  • $$9.8$$ $$m$$ $${s}^{-1}$$
  • $$4.9$$ $$m$$ $${s}^{-1}$$
  • $$19.6$$ $$m$$ $${s}^{-1}$$
  • zero
A body initially at rest travels a distance 100 m in 5 s with a constant acceleration. Find the acceleration.
  • $$20 m s^{-2}$$
  • $$4 m s^{-2}$$
  • $$8 m s^{-2}$$
  • $$10 m s^{-2}$$
A body starts from rest with a uniform acceleration $$2 m s^{-2}$$. Find the distance covered by the body in $$2\  s$$.
  • $$4\  m$$
  • $$2 \ m$$
  • $$1 \ m$$
  • $$0 \ m$$
Figure shows displacement-time graph of two vehicles A and B moving along a straight road. Which vehicle is moving faster?
202705.png
  • Vehicle A
  • Vehicle B
  • Vehicle A = Vehicle B
  • None of the above
Give an example of motion in which average speed is not zero, but the average velocity is zero.
  • A car moving with an average speed returns to the initial position
  • A car at rest
  • A car with non zero displacement.
  • All of the above.
A body is moving vertically upwards. Its velocity changes at a constant rate from $$50 m s^{-1}$$ to $$20 m s^{-1}$$ in 3 s. What is its acceleration ?
  • $$-30 m s^{-2}$$
  • $$-10 m s^{-2}$$
  • $$10 m s^{-2}$$
  • $$30 m s^{-2}$$
A body starts with an initial velocity of $$10 m s^{-1}$$ and acceleration $$5 m s^{-2}$$. Find the distance covered by it in $$5\  s$$.
  • $$112.5\  m$$
  • $$62.5\  m$$
  • $$32.5\  m$$
  • $$50\  m$$
A toy car, initially moving with a uniform velocity of $$18 \ km h^{-1}$$ comes to rest in $$2\ s$$. Find the retardation of the car in S.I units.
  • $$9  m s^{-2}$$
  • $$25  m s^{-2}$$
  • $$2.5  m s^{-2}$$
  • $$5  m s^{-2}$$
A body initially at rest starts moving with a constant acceleration $$2\ ms^{-2}$$. Calculate the distance traveled in 5 s.
  • 50 m
  • 12.5 m
  • 25 m
  • 5 m
Which of the following displacement-time graphs represents a uniform motion ?
A body moving with a constant acceleration travels the distances 3 m and 8 m respectively in 1 s and 2 s. Calculate the initial velocity.
  • $$4\, m\, s^{-1}$$
  • $$0 \, m\, s^{-1}$$
  • $$2\, m\, s^{-1}$$
  • $$1\, m\, s^{-1}$$
Figure shows the displacement-time graph for the motion of two boys A and B along a straight road in the same direction. Which of the two has greater velocity?
204425_12a1eba14e99481f834a96c3d180cbb4.png
  • B
  • A
  • Both have same velocity
  • None of the above
A train starts from rest and accelerates uniformly at a rate of  $$2\ ms^{-2}$$ for 10 s. It then maintains a constant speed for 200 s. The brakes are then applied and the train is uniformly retarded and comes to rest in 50 s. Find the maximum velocity reached.
  • $$2\, m\, s^{-1}$$
  • $$10 \, m\, s^{-1}$$
  • $$1\, m\, s^{-1}$$
  • $$20\, m\, s^{-1}$$
A train moving with a velocity of $$20\ ms^{-1}$$ is brought to rest by applying the brakes in 5 s. Calculate the retardation.
  • $$4 m s^{-2}$$
  • $$2 m s^{-2}$$
  • $$1 m s^{-2}$$
  • $$8 m s^{-2}$$
A car travels a distance 100 m with a constant acceleration and average velocity of $$20\, ms^{-1}$$. The final velocity acquired by the car is $$25\, ms^{-1}$$. Find the acceleration of the car.
  • $$1\, m\, s^{-2}$$
  • $$2\, m\, s^{-2}$$
  • $$0\, m\, s^{-2}$$
  • $$4\, m\, s^{-2}$$
When brakes are applied to a bus, the retardation produced is $$25\ \ cm\ s^{-2}$$ and the bus takes 20 s to stop. Calculate the initial velocity of the bus.
  • $$500 \, m\, s^{-1}$$
  • $$5\, cm\, s^{-1}$$
  • $$5\, m\, s^{-1}$$
  • $$12.5 \, m\, s^{-1}$$
Figure below 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?

245483_925157d32ce84222b7ece68bd28d5521.png
  • Car $$C$$
  • Car $$A$$
  • Car $$B$$
  • Can not be determined
When a ball is thrown up vertically with velocity $$ {v}_{o} $$ it reaches a maximum height of $$h$$. If one wishes to triple the maximum height then the ball should be thrown with velocity.
  • $$\displaystyle \sqrt{3}v_{0}$$
  • $$\displaystyle 3v_{0}$$
  • $$\displaystyle 9v_{0}$$
  • $$\displaystyle \frac{3}{2}v_{0}$$
What does the odometer of an automobile measure?
  • Speed
  • Distance
  • Acceleration
  • All
An object is sliding down on an inclined plane. The velocity changes at a constant rate from 10 cm/s to 15 cm/s in 2 seconds. What is its acceleration?
  • $$5 cm/s^2$$
  • $$7.5 cm/s^2$$
  • $$2.5 cm/s^2$$
  • $$12.5 cm/s^2$$
A motorboat starting from rest on a lake accelerates in a straight line at a constant rate of $$3.0\ ms^{-2}$$ for $$8\ s$$. How far does the boat travel during this time?
  • $$96\ m$$
  • $$192\ m$$
  • $$12\ m$$
  • $$72\ m$$
Which of the following relations is correct?
  • Speed = $$\frac { 1 }{ Distance\times Time } $$
  • Speed = $$\frac { Time }{ Distance } $$
  • Speed = $$\frac { Distance }{ Time } $$
  • Speed = Distance $$\times $$ Time
Which of the following is NOT matched correctly?
  • Speedometer: Speed
  • Odometer : Odour
  • Anemometer : Wind speed
  • Stopwatch : Time
The table below shows the speed of a moving vehicle with respect to time.
Speed (m/s)
2
4
6
8
10
Time (s)
1
2
3
4
5
Find the acceleration of the vehicle.
  • $$2 m/s^2$$
  • $$4 m/s^2$$
  • $$6 m/s^2$$
  • $$8 m/s^2$$
State whether given statement is True or False.
Both speed and velocity of a particle can be negative. 
  • True
  • False
A $$2\ kg$$ object has an initial velocity of $$u=10\ ms^{-1}$$. The retardation due to friction is $$2\  ms^{-2}$$. After what time does the object stop?
  • $$5\ s$$
  • $$2\ s$$
  • $$10\ s$$
  • $$8\ s$$
State whether given statement is True or False.
Is displacement independent of path?
  • True
  • False
With what speed should a car travel so that it can cover a distance of 5 km in 5 min?
  • 1 km/h
  • 5 km/h
  • 12 km/h
  • 60 km/h
A man runs $$10 \ km$$ in $$30 \ min.$$ What is his speed?
  • $$5 \ km/h$$
  • $$10 \ km/h$$
  • $$15 \ km/h$$
  • $$20 \ km/h$$
Velocity is the (distance or displacement) per unit time.
  • Displacement
  • Both Displacement and Distance
  • None 
  • Sum of both
The ratio of the heights from which two bodies are dropped is 3 : 5 respectively. The ratio of their final velocities is
  • $$\displaystyle \sqrt { 5 } :\sqrt { 3 } $$
  • $$\displaystyle \sqrt { 3 } :\sqrt { 5 } $$
  • 9 : 25
  • 5 : 3
From the displacement-time graph shown here, find the velocity of the body as it moves from B to C.
269706_c7257ce4f34a49f38811ccfab81eedee.png
  • $$0\ ms^{-1}$$
  • $$2\ ms^{-1}$$
  • $$4\ ms^{-1}$$
  • $$8\ ms^{-1}$$
Graph : Distance vs Time
270965_984f2064a0be4f5f8db0ced1dd80e038.png
  • Zero Speed
  • Constant Speed
  • Uniformly Increasing Speed
  • Uniformly Decreasing Speed
The unit for the rate of change of velocity is 
  • $$m s^{-2}$$
  • $$m s^{-3}$$
  • $$m s^{-1}$$
  • $$m^{3} s^{-2}$$
According to the following graph, what happens to the distance covered by the body from 0 -10 minutes?

266782.jpg
  • It goes on increasing
  • It goes on decreasing
  • It first increases and then decreases
  • It first decreases and then increases
The odometer of a car reads $$57321.0\ km$$ when the clock shows the time 8:30 AM. The distance moved by car if, at 8:50 AM, the odometer reading has changed to $$57336.0\ km$$ and also the speed will be:
  • $$15\ km ,\ 45\, km/h$$
  • $$10km ,$$ $$45\, km/h$$
  • $$15km ,$$ $$55\, km/h$$
  • $$20km ,$$ $$45\, km/h$$
The rear view mirror of a car is a plane mirror. A driver is reversing his car at a speed of 2 m/s. The driver sees in his rear view mirror the image of a truck parked behind his car. The speed at which the image of the truck appears to approach the driver will be ________________.
  • 1 m/s
  • 2 m/s
  • 4 m/s
  • 8 m/s
0:0:1


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