NEET Physics Ist IInd and IIIrd Laws of Motion MCQs Set A

Question. Inertia is the property of a body linked to tendency of a body
(a) to resist any change in its state
(b) to change the momentum
(c) to change its direction
(d) to change its position

Answer: A

Question. Physical independence of force is a consequence of
(a) first law of motion
(b) third law of motion
(c) second law of motion
(d) all of these

Answer: A

Question. reference frame attached to the earth
(a) cannot be an inertial frame because earth is revolving round the sun
(b) is an inertial frame because Newton's laws are applicable
(c) is an inertial frame because the earth is rotating about its own axis
(d) is an inertial frame by definition

Answer: A

Question. The direction of impulse is
(a) same as that of the net force
(b) opposite to that of the net force
(c) same as that of the final velocity
(d) same as that of the initial velocity

Answer: A

Question. A particle of mass 0.3 kg subject to a force F = – kx with k = 15 N/m . What will be its initial acceleration if it is released from a point 20 cm away from the origin ?
(a) 10 m/s²
(b) 5 m/s²
(c) 3 m/s²
(d) 15 m/s²

Answer: A

Question. A ship of mass 3 × 10⁷ kg initially at rest, is pulled by a force of 5 × 10⁴ N through a distance of 3m. Assuming that the resistance due to water is negligible, the speed of the ship is
(a) 0.1 m/sec
(b) 5 m/sec.
(c) 60 m/sec.
(d) 1.5 m/sec

Answer: A

Question. When a body is stationary
(a) the combination of forces acting on it balances each other
(b) the body is in vacuum
(c) the force acting on it is not in contact with it
(d) there is no force acting on it

Answer: A

Question. If a stone is thrown out of an accelerated train, then acceleration of the stone at any instant depends on
(a) force acting on it at that instant
(b) Both
(c) acceleration of the train
(d) None of these

Answer: A

Question. No force is required for
(a) an object moving in straight line with constant velocity
(b) an object moving in circular motion
(c) an object moving with constant acceleration
(d) an object moving in elliptical path

Answer: A

Question. A 600 kg rocket is set for a vertical firing. If the exhaust speed is 1000 ms^–1 , the mass of the gas ejected per second to supply the thrust needed to overcome the weight of rocket is
(a) 6 kg s^–1
(b) 117.6 kg s^–1
(c) 58.6 kg s^–1
(d) 76.4 kg s^–1

Answer: A

Question. An object of mass 10 kg moves at a constant speed of 10 ms^–1. A constant force, that acts for 4 sec on the object, gives it a speed of 2 ms^–1 in opposite direction. The force acting on the object is
(a) –30 N
(b) –3 N
(c) 3 N
(d) 30 N

Answer: A

Question. A player stops a football weighting 0.5 kg which comes flying towards him with a velocity of 10m/s. If the impact lasts for 1/50th sec. and the ball bounces back with a velocity of 15 m/s, then the average force involved is
(a) 625 N
(b) 500 N
(c) 1250 N
(d) 250 N

Answer: A

Question. A large force is acting on a body for a short time. The impulse imparted is equal to the change in
(a) momentum
(b) velocity
(c) energy
(d) acceleration

Answer: A

Question. China wares are wraped in straw of paper before packing. This is the application of concept of
(a) impulse
(b) acceleration
(c) momentum
(d) force

Answer: A

Question. We can derive Newton’s
(a) third and first laws from the second law
(b) All the three laws are independent of each other
(c) first and second laws from the third law
(d) second and third laws from the first law

Answer: A

Question. Swimming is possible on account of
(a) third law of motion
(b) newton's law of gravitation
(c) second law of motion
(d) first law of motion

Answer: A

Question.  A truck accelerates on a horizontal road due to the force exerted by the
(a) road
(b) earth
(c) engine
(d) driver

Answer: A

Question. Rocket engines lift a rocket from the earth surface, because hot gases with high velocity
(a) react against the rocket and push it up
(b) heat up the air which lifts the rocket.
(c) push against the earth
(d) push against the air

Answer: A

Question.  Consider the following statements and select the incorrect statement(s).
I. To move a football at rest, some one must kick it.
II. To throw a stone upwards, one has to give it an upward push.
III. A breeze causes the branches of a tree to become stationary.
IV. A strong wind can move even heavy objects.
(a) Only III
(b) III and IV
(c) I and II
(d) Only I

Answer: A

Question. A cannon after firing recoils due to
(a) Newton’s third law of motion
(b) Newton’s first law of motion
(c) backward thrust of gases produced
(d) conservation of energy

Answer: A

Question. A man is standing at the centre of frictionless pond of ice. How can he get himself to the shore?
(a) By spitting horizontally
(b) He will wait for the ice to melt in pond
(c) Unable to get at the shore
(d) By throwing his shirt in vertically upward direction

Answer: A

Question.  Law of conservation of momentum follows from
(a) Both
(b) Newton's second law of motion
(c) Newton's third law of motion
(d) None of these

Answer: A

Question. A body whose momentum is constant must have constant
(a) velocity
(b) force
(c) acceleration
(d) All of these

Answer: A

Question. In an explosion, a body breaks up into two pieces of unequal masses. In this
(a) both parts will have numerically equal momentum
(b) lighter part will have more momentum
(c) heavier part will have more momentum
(d) both parts will have equal velocity

Answer: A

Question. An explosion breaks a rock into three parts in a horizontal plane. Two of them go off at right angles to each other. The first part of mass 1 kg moves with a speed of 12 ms^–1 and the second part of mass 2 kg moves with speed 8 ms^–1. If the third part flies off with speed 4 ms–1 then its mass is
(a) 5 kg
(b) 7 kg
(c) 17 kg
(d) 3 kg

Answer: A

Question.  A spacecraft of mass 100 kg breaks into two when its velocity is 10⁴ m s^–1. After the break, a mass of 10 kg of the space craft is left stationary. The velocity of the remaining part is
(a) 11.11 × 10³ m s^–1
(b) 10⁴ m s^–1
(c) 10³ m s^–1
(d) 11.11 × 10² m s^–1

Answer: A

Question. A ball is thrown up at an angle with the horizontal. Then the total change of momentum by the instant it returns to ground is
(a) weight of the ball × total time of flight
(b) weight of the ball × horizontal range
(c) weight of the ball × half the time of flight
(d) acceleration due to gravity × total time of flight

Answer: A

Question.  The net force on a rain drop falling down with a constant speed is ________
(a) zero
(b) viscous drag of air F
(c) weight of drop W
(d) W + F + force of buoyany

Answer: A

Question. A body is imparted motion from rest to move in a straight line. If it is then obstructed by an opposite force, then
(a) the body is sure to slow down
(b) the body will necessarily continue to move in the same direction at the same speed
(c) None of these
(d) the body may necessarily change direction

Answer: A

Question.  A ball of mass 10 g moving perpendicular to the plane of the wall strikes it and rebounds in the same line with the same velocity. If the impulse experienced by the wall is 0.54 Ns, the velocity of the ball is
(a) 27 ms^–1
(b) 3.7 ms^–1
(c) 54 ms^–1
(d) 37 ms^–1

Answer: A

Question.  A hammer weighing 3 kg strikes the head of a nail with a speed of 2 ms^–1 drives it by l cm into the wall. The impulse imparted to the wall is
(a) 6Ns
(b) 3Ns
(c) 2Ns
(d) l2 Ns

Answer: A