Tag: momentum and newton's laws

Questions Related to momentum and newton's laws

Statement 1 : There can be displacement of an object even in the absence of any force acting on it.
Statement 2 : An object in uniform motion in a straight line shows displacement even when the net force acting on it is zero.

physics force and newton's laws of motion first law of motion newton's first law of motion momentum and newton's laws

  1. Both statement 1 and statement 2 are true and statement 2 is correct explanation of statement 1

  2. Both statement 1 and statement 2 are true, but statement 2 is not correct explanation of statement 1

  3. Statement 1 is true but statement 2 is false

  4. Statement 1 is false but statement 2 is true

Show answer
Correct Option: A
Explanation:

Answer is A.

If any body is in the state of rest or in uniform motion, it remains in that state until an external force is applied on it. 
So, if a body is initially moving with some constant velocity, it can continue to move with same velocity even if no external force is acting on it.
In fact, the effect of force is to accelerate and not just displace. For example, an object moving straight in space far away from any celestial objects will continue to move forever, although there is no force acting on it. This is due to Newton's first law of motion or law of inertia.
Hence, Both statement 1 and statement 2 are true and statement 2 is correct explanation of statement 1.

Newton's law of motion were published in the year 1699:

physics force and newton's laws of motion first law of motion newton's first law of motion momentum and newton's laws

  1. True

  2. False

Show answer
Correct Option: B
Explanation:

Newton's laws of motion published in $1687$ by the scientist $Issac$ $Newton$ in his Philosophiae Naturalis Principia Mathematica (Mathematical Principles of Natural Philosophy).

While dusting a carpet, we give it a sudden jerk or beat it with a stick because: 

physics force and newton's laws of motion first law of motion newton's first law of motion momentum and newton's laws

  1. the inertia of rest keeps the dust in its position and the dust is removed when the carpet moves away.

  2. the inertia of motion removes dust.

  3. no inertia involved in process.

  4. jerk compensates for the force of adhesion between dust and carpet and dust is removed.

Show answer
Correct Option: A
Explanation:

While dusting we give a sudden serk our beat with stick because when we do that stick because when we do that the particle of carpet move with our help and the dust particle stays at rest by inertia and eventually they separate from the carpet.

Physical independence of force is a consequence of:

physics force and newton's laws of motion first law of motion newton's first law of motion momentum and newton's laws

  1. Newton's third law of motion

  2. Newton's second law of motion

  3. Newton's first law of motion

  4. All of these

Show answer
Correct Option: C
Explanation:

Newton''s first law of motion is related to physical independence of force.

Hence,
option $C$ is correct answer.

A person sitting in an open car moving at constant velocity throws a ball vertically up into air. Where will the ball fall?

physics force and newton's laws of motion first law of motion newton's first law of motion momentum and newton's laws

  1. Outside the car

  2. In the car ahead of the person

  3. In the car to the side of the person

  4. Exactly in the hand from which it was thrown up

Show answer
Correct Option: D
Explanation:

The ball has forward velocity equal to the velocity of the car even when ball is given velocity upwards.

So, the ball will cover the same distance as that by the car, and hence it will land in the hands of the person.

Who among the following anticipated Newton by declaring that all things gravitate to the earth?

physics force and newton's laws of motion first law of motion newton's first law of motion momentum and newton's laws

  1. Buddhagupta

  2. Varahamihira

  3. Aeyabhatta

  4. Brahmagupta

Show answer
Correct Option: D
Explanation:

Brahmagupta  the  anticipated Newton by declaring that all things gravitate to the earth.

Hence,
option $D$ is correct answer.

Inertia is the property of a body which preserves its state of motion or uniform motion in a straight line. The following factors tell me about inertia.
I. Greater the mass of a body, greater is its inertia.
II. Greater the inertia of a body, the less will be the acceleration produced by a given force.
III. The law of inertia is the same as Newton's first law of motion. 
Which combination is true?

physics force and newton's laws of motion first law of motion newton's first law of motion momentum and newton's laws

  1. I and III only

  2. I and II only

  3. I, II and III

  4. II and III only

Show answer
Correct Option: C

A block is moved from rest through a distance of 4m along a straight line path.The mass of the block is 5 kg,and the  force acting on it is 20 N.If the kinetic energy acquired by the block be 40J,at what angle to the path the force is acting:

physics force and newton's laws of motion first law of motion newton's first law of motion momentum and newton's laws

  1. $30^o$

  2. $60^o$

  3. $45^o$

  4. none of the above

Show answer
Correct Option: B
Explanation:
From work Energy theorem 
$ \triangle w = \triangle KE $ 
$ F.S = K.E $
$ F.S cos\theta = KE  $
$ cos\theta = \frac{KE}{FS} $
$ cos\theta = 1/2 $
$ \theta = 60^{\circ} $