CBSE Questions for Class 11 Engineering Physics Motion In A Straight Line Quiz 5 - MCQExams.com

How much time elapses during this interval?
  • 5 s
  • 20 s
  • 10 s
  • 1 s
A ball is thrown vertically upwards with a certain initial velocity. Assume that there is no resistance due to air. Among the graphs below, the graph that is not an appropriate representation of the motion of the ball is:-
  • A
  • B
  • C
  • D
Consider two observers moving with respect to each other at a speed $$v$$ along a straight line. They observe a block of mass $$m$$ moving a distance $$l$$ on a rough surface. The following quantities will be same as observed by the two observers.
  • Kinetic energy of the block at time t
  • Work done by friction
  • Total work done on the block
  • Acceleration of the block
An observer finds the magnitudes of the acceleration of two bodies to be the same. This necessary implies that the two bodies.
  • are at rest with respect to each other
  • are at rest or move with constant velocities with respect to each other
  • are accelerated with respect to each other
  • may be at rest, moving with constant velocities or accelerated with respect to each other
A car of mas sm starts moving so that its velocity varies according to the law $$v = \beta\, \sqrt{s}$$  where $$\beta$$ is a constant, ands is the distance covered. The total  work performed by all the forces which are acting on the car during the first t seconds after the beginning of motion is 
  • $$m\beta^{4}t^{2}/8$$
  • $$m\beta^{2}t^{4}/8$$
  • $$m\beta^{4}t^{2}/4$$
  • $$m\beta^{2}t^{4}/4$$
A block of mass m is suspended by a light thread from an elevator.The elevator is accelerating upward with uniform acceleration a. The work done by tension on  the block during t seconds is (1 = 0) :
293153_ee06287d2dae4e90a0568a550a3d0780.png
  • $$\displaystyle \frac{m}{2} (g + a) at^{2}$$
  • $$\displaystyle \frac{m}{2} (g - a) at^{2}$$
  • $$\displaystyle \frac{m}{2} gat^{2}$$
  • 0
The speed of the particle moving along with straight line become half after every next second. The initial speed is $$V_0$$. The total distance travelled by the particle will be
  • $$V_0$$
  • $$2V_0$$
  • $$\infty $$
  • None of the above
A car is moving with a uniform velocity of 40 km h$$^{-1}$$ in straight line. Its acceleration after 1 hour is:
  • 40 km h$$^{-1}$$
  • 20 km h$$^{-1}$$
  • 30 km h$$^{-1}$$
  • zero
A truck of mass $$2800 kg$$ is moving with a speed of $$15\:m/s$$. A frictional retarding force of $$1200 N$$ are acting on it, then in $$10 s$$ it shall travel a distance of:
  • $$156 m$$
  • $$122.8 m$$
  • $$162.5 m$$
  • $$118 m$$
The dispIacement of a body is given by $$2s\, =\, gt^2$$ where g is a constant. The velocity of the body at any time t is: 
  • $$gt$$
  • $$\dfrac{gt }{ 2}$$
  • $$\dfrac{gt^2} {2}$$
  • $$\dfrac{gt^3}{ 6}$$
$$A$$ and $$B$$ are arguing about uniform acceleration. $$A$$ states that acceleration means "the longer you go." $$B$$ states that acceleration means "the further you go." Who is right?
  • $$A$$
  • $$B$$
  • Both $$A$$ and $$B$$
  • None of these
A ball is thrown upwards in a train which is accelerating. The ball will fall ______________.
  • ahead of the thrower
  • behind the thrower
  • in the hands of thrower
  • data inadequate
A body under uniformly accelerated motion covers $$20   m$$ and $$60   m$$ in first two seconds of time from the beginning. The body starts with an initial velocity
  • Zero
  • $$5{m}/{s}$$
  • $$10{m}/{s}$$
  • $$15{m}/{s}$$
A truck increases its speed from $$10km/h$$ to $$50 km/h$$ in $$20$$ seconds. Its acceleration is:
  • $$0.55 m/s^2$$
  • $$2.55 m/s^2$$
  • $$0.75 m/s^2$$
  • $$8.65 m/s^2$$
 Which one of the following represents the displacement-time graph of two objects a and b moving with zero relative speed ? 
  • None of these
A ball is thrown vertically upwards with a velocity $$u$$. What is the maximum height to which it will rise before falling back?
  • $${u^2/2g}$$
  • $$g/u$$
  • $$2g/u$$
  • $$u/2g$$
A ball is dropped on the floor from a height of 10 m. It rebounds to a height of 2.5 m.If the ball is in contact with the floor for 0.01 sec, then average acceleration during contact is 
  • $$\displaystyle 2100{ m }/{ { s }^{ 2 } }$$
  • $$\displaystyle 1400{ m }/{ { s }^{ 2 } }$$
  • $$\displaystyle 700{ m }/{ { s }^{ 2 } }$$
  • $$\displaystyle 400{ m }/{ { s }^{ 2 } }$$
If a car at rest accelerates uniformly and attains a speed of 72 km/hr in 10 s, then it covers a distance of:
  • 50 m
  • 100 m
  • 200 m
  • 400 m
A rocket is launched to travel vertically upward with a constant velocity of 20 m/s. After travelling 35 s the rocket develops a snag and its fuel supply is cut off. The rocket then travels like a free body, the height achieved it is
  • 600 m
  • 720 m
  • 800 m
  • 820 m
A block is released from rest at the top of a frictionless inclined plane 16 m long. It reaches the bottom 4 sec later. A second block is projected up the plane from the bottom at the instant the block is released in such a way that it returns to the bottom simultaneously with first block. The acceleration of each block on the incline is 
  • $$\displaystyle 1{ m }/{ { s }^{ 2 } }$$
  • $$\displaystyle 2{ m }/{ { s }^{ 2 } }$$
  • $$\displaystyle 4{ m }/{ { s }^{ 2 } }$$
  • $$\displaystyle 9.8{ m }/{ { s }^{ 2 } }$$
A stone dropped from the top of a building taken 5 s to reach the ground. If it is stopped momentarily 4 s after it is dropped and then released again, how much time would it take from the moment it is released again to reach the ground? $$\displaystyle (Take\quad g = 10 {ms} ^{-2})$$
  • 1 s
  • 3 s
  • 4 s
  • 5 s
A body, when dropped from a certain height, falls to the ground in 4 s. What is the time taken by the body to cover the last 100 cm? $$\displaystyle (Take\quad g={ 10\quad ms }^{ -2 })$$
  • $$0.65 s$$
  • $$0.15 s$$
  • $$0.125 s$$
  • $$0.025 s$$
The distance travelled by a body starting with a velocity of $$\displaystyle 20\ { ms }^{ -1 }$$, and moving with an acceleration of $$\displaystyle 2\ { ms }^{ -2 }$$, in the $$\displaystyle { 8 }^{ th }$$ second is ____ m.
  • 35
  • 20
  • 120
  • 10
An automobile travelling with a speed of $$\displaystyle 72 km {h}^ {-1} $$ , can be stopped within a distance of 30 m, by applying brakes. What will be the stopping distance, if the automobile speed is increased to $$\displaystyle \sqrt { 3 } $$ times and the same braking force is applied?
  • 30 m
  • 90 m
  • 60 m
  • 120 m
A stone thrown vertically passes a certain point P at the end of 2 seconds and 8 seconds respectively. Find the maximum height reached by the stone .$$\displaystyle (Take\quad g ={ 10\quad ms }^{ -2 }) $$
  • 625 m
  • 125 m
  • 225 m
  • 350 m
A stone is released from a hot air balloon which is rising steadily with a velocity of $$\displaystyle { 4\quad ms }^{ -1 }$$. The velocity of the stone at the end of 3 s after it is released is  _____ $$\displaystyle { ms }^{ -1 }$$
  • 29.4
  • 25.4
  • 32.5
  • 62.7
A body starts moving with an initial velocity of $$\displaystyle 5\ { ms }^{ -1 }$$ and an acceleration of $$\displaystyle 1\ { ms }^{ -2 }$$. The distance travelled by it in the 5th second is 
  • $$9.5$$ m
  • $$22.5$$ m
  • $$50$$ cm
  • $$10$$ cm
A hollow iron ball (A) and a solid iron ball (B) and cricket ball (C) are dropped from the same height. Which among the three balls reaches the ground first? Assuming there is no resistance due to air.
  • A
  • B
  • C
  • All the three balls reaches ground simultaneously
The ratio of the time taken by a body moving with uniform acceleration in reaching two points P and Q along a straight line path is 1 :If the body starts from rest and moves linearly, the ratio of the distance between P and Q from the starting point is:
  • 4 : 1
  • 1 : 4
  • 2 : 3
  • 3 : 1
A body starts from rest and moves with uniform acceleration for 3s. It then decelerates uniformly for 2s. and stops. If the deceleration is $$\displaystyle 3 \ { ms }^{ -2 }$$ the maximum velocity of the body is ____ $$\displaystyle { ms }^{ -1 }$$
  • zero
  • 2
  • 6
  • Cannot be determined
A stone projected up vertically with a velocity v, reaches points x, y and z in its path with velocities $$\displaystyle \frac { v }{ \sqrt { 5 }  } ,\frac { v }{ \sqrt { 10 }  } and\frac { v }{ \sqrt { 15 }  } $$ respectively. Find the ratio xy : yz.
  • 3:1
  • 4:1
  • 6:1
  • 3:2
A bike moving along a straight road covers $$35$$ m in the $$4$$th second and $$40$$ m in the $$5$$th second. What is its initial velocity and acceleration (if the acceleration is assumed to be uniform )? 
  • $$\displaystyle { 17.5\ ms }^{ -1 }$$
  • $$\displaystyle { 8\ ms }^{ -1 }$$
  • $$\displaystyle { 7.8\ ms }^{ -1 }$$
  • $$\displaystyle { 38.5\ ms }^{ -1 }$$
A body is projected horizontally from a certain height, (h) then time of descent is 
  • $$\displaystyle { t }_{ d }=\sqrt { \frac { 2h }{ g } } $$
  • $$\displaystyle { t }_{ d }=\sqrt { \frac { h }{ g } } $$
  • $$\displaystyle { t }_{ d }=\sqrt { h g} $$
  • $$\displaystyle { t }_{ d }=\sqrt { h + g} $$
Find the initial velocity of projection of a ball thrown vertically up if the distance moved by it in 3rd second is twice the distance covered by it in 5th second.$$\displaystyle (Take g = 10\ { ms }^{ 2 })$$
  • $$\displaystyle 45\ { ms }^{ -1 }$$
  • $$\displaystyle 75\ { ms }^{ -1 }$$
  • $$\displaystyle 20\ { ms }^{ -1 }$$
  • $$\displaystyle 85\ { ms }^{ -1 }$$
A stone is dropped by a person from the top of a tower, which is 200 m tall. At the same time another stone is thrown upwards, with a velocity of $$\displaystyle 50\ { ms }^{ -1 }$$  by a person standing at the foot of the tower. Find the time after which two stones meet.
394205.JPG
  • $$4 \ s$$ 
  • $$5 \ s$$
  • $$8\ s$$
  • $$10\ s$$
A body starts from rest and moves with uniform acceleration for 2s. If then decelerates uniformly for 3s and stops. If deceleration is $$\displaystyle { 4\quad ms }^{ -2 }$$, the acceleration of the body is ____ $$\displaystyle {  ms }^{ -2 }$$
  • 10
  • 8.7
  • 4
  • 6
Two cars arrive at certain point with velocity of $$\displaystyle { 30\ ms }^{ -1 } , { 25\ ms }^{ -1 } $$ and travel in a straight line with uniform acceleration $$\displaystyle { 0.25\ ms }^{ -2 }\ and\  { 0.5\ ms }^{ -2 } $$ respectively.
(A) Find the distance at which they meet again.
(B) Also determine the time after which the final velocity one of the cars is equal to the initial velocity of the other.
  • $$1400 \ m$$ , $$10\ s$$
  • $$2800 \ m$$ , $$20\ s$$
  • $$1400 \ m$$ , $$30\ s$$
  • $$1000 \ m$$ , $$10\ s$$
When a body is dropped from a tower, it covers 75% of total height of the tower in the last second of its fall. What is the total height of the tower? 
  • $$4.9$$ m
  • $$ 9.8$$ m
  • $$5.6$$ m
  • $$6.0$$ m
A freely falling body crosses points P, Q and R with velocity V, $$2$$V and $$3$$V respectively. Find the ratio of the distance PQ to QR.
  • $$5 : 3$$
  • $$3 : 5$$
  • $$1 : 2$$
  • $$2 : 1$$
A car moves with a constant velocity of $$\displaystyle { 10\ ms }^{ -1 }$$ for 10 s along a straight road. Then it moves with uniform acceleration of $$\displaystyle { 2\ ms }^{ -2 }$$ for $$5$$ seconds. Find the total displacement at the end of the 15 s of its motion. 
  • $$175$$ m
  • $$125$$ m
  • $$150$$ m
  • $$105$$ m
A body is dropped from a height of $$2$$ m. It penetrates into the sand on the ground through a distance of $$10$$ cm before coming to rest. What is the retardation of the body in sand? 
  • $$\displaystyle -9.8\ {ms} ^{-1}$$
  • $$\displaystyle 196\ {ms} ^{-2}$$
  • $$\displaystyle -196\ {ms} ^{-2}$$
  • $$\displaystyle 9.8\ {ms} ^{-2}$$
A body falls from a height of $$45$$ m above the ground. Find the time taken by the body to reach the ground. $$\displaystyle (Take \ g = 10 { ms }^{ -2 })$$
  • $$5$$ s
  • $$2$$ s
  • $$3$$ s
  • $$6$$ s
Two stones A and B are dropped from the top of two different towers such that they travel $$44.1$$ m and $$63.7$$ m in the last second of their motion respectively. Find the ratio of the heights of the two towers from where the stones were dropped.
  • $$16 : 25$$
  • $$7 : 9$$
  • $$5 : 7$$
  • $$25 : 49$$
An object projected vertically up from the top of the tower took $$5$$ s to reach the ground. The average velocity of the object is  $$\displaystyle 5 { ms }^{ -1 })$$, find its average speed. (given  $$\displaystyle g\ = 10 { ms }^{ -1 })$$.
  • $$\displaystyle 65\ { ms }^{ -1 }$$
  • $$\displaystyle 13\ { ms }^{ -1 }$$
  • $$\displaystyle 26\ { ms }^{ -1 }$$
  • $$\displaystyle 25\ { ms }^{ -1 }$$
A ball thrown vertically upwards with speed 'u' from the top of a tower reaches the ground in $$9$$ s. Another ball is thrown vertically downwards from the same position with speed 'u', takes $$4$$ s to reach the ground. Calculate the value of 'u' . $$\displaystyle (Take \ g= 10 { ms }^{ -1 })$$ 
  • $$\displaystyle 125\ { ms }^{ -1 }$$
  • $$\displaystyle 75\ { ms }^{ -1 }$$
  • $$\displaystyle 25\ { ms }^{ -1 }$$
  • $$\displaystyle 175\ { ms }^{ -1 }$$
A ball which is thrown vertically up from the top of the tower reaches the ground in $$12$$ s. Another ball thrown vertically downwards from the same position with the same velocity takes $$4$$ s to reach the ground. Find the height of the tower. $$\displaystyle (Take\ g = 10 {ms}^{-2} ) $$
  • $$180$$ m
  • $$120$$ m
  • $$220$$ m
  • $$240$$ m
An object travels 10 s with uniform acceleration along a straight line path. During this period if the velocity of the object is increased from $$\displaystyle { \ 5\ ms }^{ -1 } to { \ 25\ s }^{ -1 }$$, then find the distance travelled by the body?
  • $$150$$ m
  • $$100$$ m
  • $$125$$ m
  • $$175$$ m
A body is dropped from a certain height 'h' meters. Assuming that the gravitational field is nullified, after the body has travelled $$\dfrac{h}{2}$$ meters such that g $$= 0, $$discuss the motion of the body. Find an expression for the time taken by the body to reach the ground.   
  • $$\displaystyle \dfrac { 3 }{ 2 } \sqrt { \dfrac { h }{ g } } $$
  • $$\displaystyle\sqrt { \dfrac { g }{ h } } $$
  • $$\displaystyle \sqrt { gh } $$
  • $$\displaystyle \dfrac { 1 }{ 2 } \sqrt { gh } $$
A ball thrown vertically upwards with speed 'u' from the top of a tower reaches the ground in $$9$$ s. Another ball is thrown vertically downwards from the same position with speed 'u'. take $$4$$ s to reach the ground. Calculate the value of 'u'. $$\displaystyle (Take \quad g = 10 { ms }^{ -2 })$$ 
  • $$\displaystyle 15\  { ms }^{ -1 }$$
  • $$\displaystyle 20\ { ms }^{ -1 }$$
  • $$\displaystyle 25\ { ms }^{ -1 }$$
  • $$\displaystyle 45\ { ms }^{ -1 }$$
A ball is thrown vertically upwards with an initial velocity such that it can reach a maximum height of 15 m, if at the same instance a stone is dropped from the same height of 15 m, find the ratio of distances travelled by them when they cross each other?
  • $$4 : 3$$
  • $$2 : 3$$
  • $$1 : 2$$
  • $$3 : 1$$
0:0:1


Answered Not Answered Not Visited Correct : 0 Incorrect : 0

Practice Class 11 Engineering Physics Quiz Questions and Answers