CBSE Questions for Class 11 Engineering Physics Motion In A Straight Line Quiz 14 - MCQExams.com

Two cyclists are travelling the same distance at the speed of $$10$$ km\hr and $$15$$ km\hr respectively. If one cyclist takes $$40$$ minutes or more to cover the distance, then what distance (in km) are they travelling?
  • $$18$$ km
  • $$20$$ km
  • $$15$$ km
  • $$12$$ km
A system is shown in the figure and man is pulling the rope from both sides with constant speed $$'u'$$. Then the speed of the block will be ($$M$$ moves vertically):
1156709_60d2bb0c35f14087828473490c640a8d.png
  • $$\dfrac{3u}{4}$$
  • $$\dfrac{3u}{2}$$
  • $$\dfrac{u}{4}$$
  • None of these
A ball is dropped from a height of $$7.2$$m. It bounces back to $$3.2$$m after striking the floor. The ball remains in contact with the floor for $$20$$ms. Given that $$g=10 ms^{-2}$$, the average acceleration of the ball during the contact is:
  • $$100 ms^{-2}$$
  • $$200 ms^{-2}$$
  • $$600 ms^{-2}$$
  • $$1000 ms^{-2}$$
An object is tossed vertically into the air with an initial velocity of 8 m/s. Using the sign convention upwards as positive, how does the vertical component of the acceleration $$a_y$$ of the object (after leaving the hand) vary during the flight of the object?
o
  • On the way up $$a_y > 0$$, on the way down $$a_y > 0$$
  • On the way up $$a_y < 0$$, on the way down $$a_y > 0$$
  • On the way up $$a_y > 0,$$ on the way down $$a_y < 0$$
  • On the way up $$a_y <0$$, on the way down $$a_y < 0$$
A scooterist is moving on a straight road with speed $$10\;m{s^{ - 1}}$$ . A bus ahead of scooterist by 32 m, starts from rest with an acceleration $$1\;m{s^{ - 2}}$$, if both are moving in the same direction then the time after which scooter overtakes the bus is:
  • $$16$$ s
  • $$4$$ s
  • $$8$$ s
  • It cannot overtake the bus
A particle initially at rest starts moving in a straight line with constant accelration. it attains a speed of $$10m/s$$ in 2s after which it deaccelerates with constant rate and comes to rest in the next 3 seconds.An average speed of the particle during the entire motion will be 
  • $$5m/s$$
  • $$10m/s$$
  • $$15m/s$$
  • $$20m/s$$
A balloon is rising with unifrom speed $$14\;m{s^{ - 1}}$$ .At a height $$98 m$$ from the ground a stone is dropped from the balloon.The time taken by the stone to strike the ground is $$\left( {g = 10\;m/{s^2}} \right)$$:
  • $$40 s$$
  • $$57.8 s$$
  • $$60 s$$
  • $$36 s$$
A rocket of initial mass $$5000 kg$$ ejects gets at a constant rate of $$60kg/s$$ with a relative speed of $$2050 m/s$$. Acceleration of the rocket 15 second after it is blasted off from the surface of earth will be ($$g = 10m/{s}^{2}$$?)
  • $$10m/{s}^{2}$$
  • $$20m/{s}^{2}$$
  • $$30m/{s}^{2}$$
  • $$40m/{s}^{2}$$
A stone $$A$$ is thrown vertically upward with speed $$u$$ and another stone $$B$$ is thrown vertically downward with same speed $$u$$ from a height $$h$$. The time taken by stone $$A$$ and $$B$$ to reach the ground are $$16\ s$$ and $$4\ s$$ respectively. The time taken by another stone to reach the ground after it has been dropped from height $$H$$ is [Take $$g=10\ m/s^{2}$$]
  • $$2\sqrt{10}\ s$$
  • $$10\ s$$
  • $$8\ s$$
  • $$40\ s$$
A particle slides down a smooth inclined plane of elevation $$\theta$$ fixed in the elevator going up with an acceleration $$a_0$$ as shown. The base of the incline has length $$L$$. Then the time taken by the particle to reach the bottom of the plane is given by:
1204523_bc24a5b585ea4e06aeddd20c2279a345.png
  • $$\sqrt{\dfrac{2L}{(g+a_0)\sin\theta}}$$
  • $$\sqrt{\dfrac{2L}{(g+a_0)\sin\theta \cos\theta}}$$
  • $$\sqrt{\dfrac{2L}{g\sin\theta \cos\theta}}$$
  • None of the above
Balls are dropped from the roof of a tower at a fixed interval of time. At the moment when $$9 ^ { \text { th } }$$ ball reaches the ground $$\mathrm { n } ^ { \text { th } }$$ ball is at $$3 / 4 ^ { \text { th } }$$ height of tower. The value of $$n$$ is:
  • $$13$$
  • $$7$$
  • $$6$$
  • $$5$$
A stone thrown upwards with a velocity u reaches upto a height h. If the initial velocity is 2u the height attained would be
  • $$2h$$
  • $$4h$$
  • $$8h$$
  • $$16h$$
A clean body of mass $$100\  g$$ starts moving with a velocity of $$2\ m/s$$ on a smooth horizontal plane and it accumulates dust at the rate of $$5\ g/s$$ . The velocity of body after $$20\ s$$ will be 
  • $$0.5\ m/s$$
  • $$1\ m/s$$
  • $$2\ m/s$$
  • $$4\ m/s$$
A body moves with a velocity of 3 m/s due east and then turns due north to travel with the same velocity. If the total time of travel is 6s, the acceleration of the body 
  • $$\sqrt 3 m/s^2$$ towards north west
  • $$\frac{1}{\sqrt 2} m/s^2$$ towards north west
  • $$\sqrt 2 m/s^2$$ towards north east
  • all the above
Two persons start running towards each other from two points that are 120 m apart. First person runs with a speed of $$5\;m{s^{ - 1}}$$ and the other with a speed of $$7\;m{s^{ - 1}}$$.Both the persons meet after 
  • 10 s
  • 24 s
  • 1 min
  • 48 s

Burglars, after looting a bank, jump into a waiting van at rest and speed up along a straight road at a constant rate of $$2.0{\text{ m}}{{\text{s}}^{ - 2}}$$ . At that instant, a police jeep moving at a constant speed of 30 m/s is 300m behind the burglars moving in the same direction. Choose the correct statement from the following;
  • the police with not be able to catch the burglars
  • the shortest distance between the police and the burglars is 75m
  • The shortest distance between the police and the burglars is 125m
  • The police can catch the burglars if they accelerate at a constant rate of $$0.5{\text{ m}}{{\text{s}}^{ - 2}}$$
A ball is dropped freely while another is thrown vertically downward with an initial velocity of $$\dfrac{v}{2}$$ from the same point simultaneously. After 't' second they are separated by a distance of?
  • $$\dfrac{vt}{2}$$
  • $$\dfrac{1}{2}gt^2$$
  • $$vt$$
  • $$\dfrac{vt+gt^2}{2}$$
A rocket is projected at the surface of earth like that in which acceleration 19.6 $$m/s^{2}$$ produces. After 5 seconds if stops its engine then calculate the following before to come at the surface of the earth.
  • Maximum height obtained by rocket
  • The velocity of the rocket at the time of reach it in the surface.
  • Total time of journey
  • The graph between velocity-time and acceleration - time.
A stone dropped from a building of height $$h$$ and it reaches after $$h$$ seconds on earth. From the same building if two stones are thrown (one upwards and other downwards) with the same velocity $$u$$ and they reach the earth surface after $$t_1$$ and $$t_2$$ seconds respectively, then 
  • $$t = t _ { 1 } - t _ { 2 }$$
  • $$t = \dfrac { t _ { 1 } + t _ { 2 } } { 2 }$$
  • $$t = \sqrt { t _ { 1 } t _ { 2 } }$$
  • $$t = \sqrt { t _ { 1 } ^ { 2 } + t _ { 2 } ^ { 2 } }$$
A particle is moving in a straight line with initial velocity u and uniform acceleration a .If the sum of the distances travelled in $$ t^{th}$$ and $$ (t+1)^{th}$$ seconds is 100 cm, then its velocity after t seconds in $$ cm s^{-1}$$ is 
  • 20
  • 30
  • 50
  • 80
A balloon of total mass 1000kg float motionless over the earth's surface. If 100kg or sand ballast are thrown over board, the balloon starts to rise with an acceleration of
  • $$10 m/s^{2}$$
  • $$9.8 m/s^{2}$$
  • $$1.09 m/s^{2}$$
  • $$4.9 m/s^{2}$$

When a stone falling from the top of the vertical tower has fallen a distance x m, another is let fall from a point y m below the top. If the fall from rest and reach the ground together, then the height of the tower is 
  • $$\dfrac{{{{\left( {x + y} \right)}^2}}}{{4x}}{\text{m}}$$
  • $$\dfrac{{4{{\left( {x + y} \right)}^2}}}{{x}}{\text{m}}$$
  • $$\dfrac{{4x}}{{{{\left( {x + y} \right)}^2}}}{\text{m}}$$
  • $$4x{\left( {x + y} \right)^2}{\text{m}}$$
A particle is falling under gravity. In first $$t$$ second it covers $$s_{1}$$ and in the next $$t$$ seconds it covers $$s_{2}$$ then $$t$$ is given by
  • $$\sqrt{\dfrac{s_{2}-s_{1}}{2g}}$$
  • $$\sqrt{\dfrac{s_{2}-s_{1}}{g}}$$
  • $$\sqrt{\dfrac{s_{2}--s_{1}}{2g}}$$
  • $$\sqrt{\dfrac{s_{2}^{2}-s_{1}2}{2g}}$$
Two bodies of masses $$1 kg$$ and $$3 kg$$ obliquely projected in opposite direction towards each other. Their velocities are $$15 ms^{-1}$$ and $$5 \sqrt 3 ms^{-1}$$ and angle made with horizontal are $$30^o$$ and $$60^o$$ respectively. They collide and stick to each other at a point when both of them reach maximum height. What is the final velocity with which the combined mass hits the ground ? $$(g=10 ms^{-2})$$
  • $$2.5 ms^{-1}$$
  • $$7.5 ms^{-1}$$
  • $$5 ms^{-2}$$
  • $$15 ms^{-1}$$
A tiger chases a deer $$30m$$ ahead of it and gains $$3\ m$$ in $$5\ s$$ after the chase began. The distance gained by the tiger in $$10\ s$$ is
  • $$6\ m$$
  • $$12\ m$$
  • $$18\ m$$
  • $$20\ m$$
A body travels  $$200\mathrm { cm }$$  in the first two seconds and  $$220\mathrm { cm }$$  in the next four second. The velocity at the end of the seventh second from the start will be (acceleration is constant)
  • $$10 \mathrm { cm } / \mathrm { s }$$
  • $$5 \mathrm { cm } / \mathrm { s }$$
  • $$15 \mathrm { cm } / \mathrm { s }$$
  • $$20 \mathrm { cm } / \mathrm { s }$$
To an observer moving along East, the wind appear to blow from North. If the doubles his speed, the air would appear to come from-
  • North
  • East
  • North-East
  • North-West
A body starting from rest is moving with a uniform acceleration of 8 $$m/{s^2}.$$ Then the distance travelled by it in 5th second will be.
  • 40 m
  • 36 m
  • 100 m
  • zero.
Two particles $$A$$ and $$B$$ are initially located on $$y-axis$$ with distance $$l$$ apart. They start moving at time $$t = 0$$ such that the velocity $$\vec u$$ of $$B$$ is always along the $$x-axis$$ and velocity $$\vec v$$ of $$A$$ is continuously aimed at $$B.$$ At $$t = 0, \vec { u }$$ is perpendicular to $$\vec { v }.$$ The particles will meet after time
  • $$\dfrac { u l } { v ^ { 2 } - u ^ { 2 } }$$
  • $$\dfrac { v l } { v ^ { 2 } - u ^ { 2 } }$$
  • $$\dfrac { u l } { v ^ { 2 } + u ^ { 2 } }$$
  • $$\dfrac { v l } { v ^ { 2 } + u ^ { 2 } }$$
An object of mass $$m$$ is released from rest form the top of a smooth inclined plane of height $$h$$. Its speed at the bottom of the plane is proportional to 
  • $$m^{0}$$
  • $$m$$
  • $$m^{2}$$
  • $$m^{-1}$$
An automobile and a truck start from rest at the same instant, the automobile initially at some distance behind the truck. The truck has a constant acceleration of $$2.2m/s^{2}$$ and the automobile has an acceleration of $$3.5m/s^{2}$$. The automobile overtakes the truck when it (truck) has moved $$60m$$. How much time does it take the automobile to overtake the truck and how far behind the automobile the truck initially was ?
  • $$7.39s.35.5m$$
  • $$1.35s.15.5m$$
  • $$5.9s.15.5m$$
  • $$9.39s.35.5m$$
Two particles start moving from the same point along the same straight line .the first constant veiocity v and the second with constant accleration a. During the time that the second catch the first the greatres distance between the particles is 
  • $$\frac { { v }^{ 2 } }{ a }$$
  • $$\frac { { v }^{ 2 } }{ 2a }$$
  • $$\frac { { 2v }^{ 2 } }{ a }$$
  • $$\frac { { v }^{ 2 } }{ 4a }$$
Two bodies of different masses are dropped simultaneously from same height,If air friction acting them is directly proportional to the square of their mass then  
  • Lighter body reaches the ground earlier
  • Heavier body reaches the ground earlier
  • both reach the ground n the same time
  • Lighter body do not reach the ground
A body is moving with a uniform acceleration covers 200 m in the first 2s and 220 m in the next 4s. find the velocity in $${ms}^{-1}$$ after 7s. 
  • 10
  • 15
  • 20
  • 30
A body falling freely from rest covers $$\dfrac { 7 }{ 16 } $$ of the total height in the last second of its fall. The height from which it falls is
  • $$38.4 m$$
  • $$78.4 m$$
  • $$9.8 m$$
  • $$19.6 m$$
Particle $$A$$ and $$B$$ are moving in coplanar circular paths centred at $$O$$. They are rotating in the same sense. Time periods of rotation of $$A$$ and $$B$$ around $$O$$ are $$T_A$$ and $$T_B$$, respectively, with $$T_B > T_ A$$. Time required for $$B$$ to make one rotation around $$O$$ relative to $$A$$ is : 
1266723_285d7f44cb6d47e6ab2b6a37bae82b29.png
  • $$T _ { B } - T _ { A }$$
  • $$T _ { B } + T _ { A }$$
  • $$\frac { T _ { B } T _ { A } } { T _ { B } + T _ { A } }$$
  • $$\frac { T _ { B } T _ { A } } { T _ { A } - T _ { B} }$$
A trolley of mass 300 kg carrying sand 200 kg (in it) is moving uniformly with speed of 40km/h on a frictionless track. After a while sand starts leaking out of a hole on the track. What is the speed of the trolley after entire sand is leaked out?
  • 24km/h
  • 30km/h
  • 66km/h
  • 40km/h
A boat takes 2 hours to travel 8 km and back in still water. If the velocity of the water is 4 km/h then the time taken for going upstream of 8 km and then coming back would be 
  • 2 hours
  • 2 hours and 40 min
  • 1 hours 20 min
  • Cannot be found with the information given
A 75.0 kg man stands on a platform scale in an elevator. starting from rest, the elevator ascends, attaining its maximum speed of 1.20 m/s in 1.00 s. It travels with this constant speed for the next 10.00 s. The elevator then undergoes a uniform acceleration in the negative y direction for 1.70 s and comes to rest. What does the scale register before the elevator starts to move?
  • 84.18 kg
  • 81.48 kg
  • 75 kg
  • 65 kg
A particle starts from the origin with a velocity of $$ 10 ms^{-1} $$ and moves with a constant acceleration till the velocity increases to $$ 50 ms^{-1} $$ . at that instant, the acceleration is suddenly reversed. what will be the velocity of the particle, when it returns to the starting point?
  • Zero
  • $$ 10 ms^{-1} $$
  • $$ 50 ms^{-1} $$
  • $$ 70 ms^{-1} $$
An object is dropped from the top of a tower. the distance it covers in the last second is seven time the distance it covered in the first second . find the time of flight
  • 2 sec
  • 3 sec
  • 4 sec
  • 5 sec
A particle is moving in x-y plane . At certain instant of time. The components of its velocity and acceleration are as follows $$V_x = 3\ m/s$$, $$V_y = 4\ m/s$$, $${ a }_{ x }=2\ m/s^{ 2 }$$ and $${ a }_{ y }=1\ m/s^{ 2 }$$. The rate of change of speed at this moment is 
  • $$\sqrt { 10 } m/{ s }^{ 2 }$$
  • $$\sqrt { 4 } m/{ s }^{ 2 }$$
  • $$\sqrt { 5 } m/{ s }^{ 2 }$$
  • $$\sqrt { 2 } m/{ s }^{ 2 }$$
A lift coming down is just about to reach the ground floor. Taking the ground floor as origin and positive direction upwards for all quantities, which of the following is correct ($$x$$=displacement, $$v$$= velocity, $$a$$=acceleration):
  • $$x < o, v<0, a>0$$
  • $$x > 0, v < 0, a < 0$$
  • $$x > 0, v < 0, a> 0$$
  • $$x > 0, v >0,a >0$$
Is it possible for an object's velocity to increase while its acceleration decreases?
  • No, this is impossible because of the way in which acceleration is defined.
  • No, because if acceleration is decreasing the object will be slowing down.
  • No, because velocity and acceleration must always be in the same direction.
  • Yes, an example would be a falling object in a viscous medium, where the acceleration continuously decreases but velocity increases until a certain point. 
The position-time $$(x - t)$$ graph for a body thrown vertically upwards from ground is best shown by 
A body falls from rest under gravity and covers a distance $$44.1\ m$$ in last one second of journey. If $$g = 9.8\ m/s^2$$ then total time of fall is.
  • $$2s$$
  • $$3.18s$$
  • $$4.91s$$
  • $$5s$$
The motion of a particle is described by the law $$a = t ^ { 3 } - 3 t ^ { 2 } + 5$$ where $$a$$ is the acceleration is $$\mathrm { m } / \mathrm { s } ^ { 2 }$$ and $$t$$ is time in second. The position and velocity of the particle at $$t = 1s$$ are $$8.30m$$ and $$6.25 m/s$$. Calculate the position at $$t = 2s$$. 
  • $$10 m$$
  • $$12 m$$
  • $$15.6 m$$
  • $$14 m$$
A body moves $$4 m \text { in } 3 ^ { r d }$$ and $$12 m \text { in } 5 ^ { th }$$ second. If the motion is uniformly accelerated, how far will it travel in next $$3$$ seconds to be constant during entire motion.
  • $$60 \mathrm { m }$$
  • $$40 \mathrm { m }$$
  • $$20 \mathrm { m }$$
  • $$10 \mathrm { m }$$
A particle is moving in x-y plane . At certain instant of time. The components of its velocity and acceleration are as follows $$V_x=3\ m/s$$, $$V_y = 4\ m/s$$, $${ a }_{ x }=2\ m/s^{ 2 }$$ and $${ a }_{ y }=1\ m/s^{ 2 }$$ The rate of change of speed at this moment is 
  • $$\sqrt { 10 }\ m/{ s }^{ 2 }$$
  • $$\sqrt { 4 }\ m/{ s }^{ 2 }$$
  • $$\sqrt { 5 }\ m/{ s }^{ 2 }$$
  • $$\sqrt { 2 }\ m/{ s }^{ 2 }$$
A car starts from rest and accelerates uniformly at the rate of $$ 10 cms^{-2} $$ and reaches a maximum velocity of $$72 kmph$$. it travels with this maximum velocity for some time and retards uniformly at the rate of $$ 20 cms^{-2} $$ and comes to a stop, if the total distance covered by the body is  $$ 5 km$$, find the total time of travel of the body in sec
  • $$200$$
  • $$250$$
  • $$300$$
  • $$400$$
0:0:1


Answered Not Answered Not Visited Correct : 0 Incorrect : 0

Practice Class 11 Engineering Physics Quiz Questions and Answers