Tag: force and newton's laws of motion

Questions Related to force and newton's laws of motion

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

physics force and newton's laws of motion concept of inertia galileo's law and inertia mass and inertia

  1. Inertia of rest keeps the dust in its position and the dust is removed by movement of carpet away.

  2. Inertia of motion removes dust.

  3. No inertia involved in process.

  4. None of the above

Show answer
Correct Option: A
Explanation:

When carpet is given sudden jerk, due to inertia dust particles does not change position, while carpet moves.

Thus dust particles gets separated from carpet.
So, Option A is correct. 

Which of the following has more inertia ___

physics force and newton's laws of motion concept of inertia galileo's law and inertia mass and inertia

  1. 5Rp coin and 2Rp coin

  2. 2Rp coin and 3Rp coin

  3. 10Kg iron

  4. None of these

Show answer
Correct Option: C
Explanation:
Inertia depends upon the mass of the body. If the mass is more, inertia is more and vice versa. 10kg iron has more mass than 5Rp coin and 2 Rp coin thus its inertia is also more.
So, the correct answer is '10kg iron'.

A water tanker filled up to $\dfrac {2}{3}$rd of its height is moving with a uniform speed. On sudden application of the brake, the water in the tank would

physics force and newton's laws of motion concept of inertia galileo's law and inertia mass and inertia

  1. move backward

  2. move forward

  3. be unaffected

  4. rise upwards

Show answer
Correct Option: B
Explanation:

Basically, the law of motion is that an object at rest stays at rest and an object continues in motion until an external force acts on it.
Inertia is the resistance of any physical object to any change in its state of motion, including changes to its speed and direction. It is the tendency of objects to keep moving in a straight line at constant velocity.


So, on sudden application of brakes on the water tank, the water tank decelerates or may even stop but the water in the tank still has a tendency to move forward due to inertia. Hence the water in the tank would move forward.
A water tanker filled up to two-thirds of its height moving with a uniform speed, on sudden application of the brake, the water in the tank would move forward.

If a train is retarding and at same time coin is thrown upwards, then you will observe that:

physics force and newton's laws of motion concept of inertia galileo's law and inertia mass and inertia

  1. the coin reaches again in your hand

  2. the coin falls behind you

  3. the coin falls in front of you

  4. the coin follows a circular path

Show answer
Correct Option: C
Explanation:

At t$=$0
Velocity of train$=$v
Velocity of coin$=$v(horizontal velocity in the direction of velocity of train)
at t$=$t
Velocity of train$=$v-$\Delta$ v
Velocity of coin$=$v
Distance travelled by train after retarding$=$(v-$\Delta$v)t
Distance travelled by coin$=$v$\times$t   which is greater than distance travelled by train.
So,the coin will fall infront of you.


A football has lesser inertia than a stone of the same size because:

physics force and newton's laws of motion concept of inertia galileo's law and inertia mass and inertia

  1. Football has more air inside than the stone.

  2. Football has less air inside than the stone.

  3. Football has less mass than the stone.

  4. Football has more mass than the stone.

Show answer
Correct Option: C
Explanation:

Inertia is the property of mass. Mass of stone $>$ mass of football.

When a tree with a flexible stem is shaken vigorously,its fruits and leaves fall  own.This phenomenon can be explained by making use of

physics force and newton's laws of motion concept of inertia galileo's law and inertia mass and inertia

  1. Newton's first law of motion

  2. Newton's second law of motion

  3. Newton's third law of motion

  4. Law of conservation of momentum

Show answer
Correct Option: A
Explanation:

 

There are three types of inertia:
1. Inertia of rest: This is the resistance offered by the body to remain in rest unless an external force is not applied on the body. Eg. : If a carpet is beaten with a stick then the dust particles due to inertia of rest tends to remain in rest while the fibres of carpet becomes in motion.


2. Inertia of direction: This is the resistance offered by the body to change its direction unless an ext. force is not applied on the body. Eg : If a bus takes a turn then passengers sitting in tends to remain in the same direction in which the bus was travelling before.


3. Inertia of motion: The resistance offered by the body to change its uniform motion. Eg : If a bus stops suddenly then the passengers fall forward due to inertia of motion

So when we shake a tree, due to inertia of motion the fruit tries to remain in motion. Due to which it gets detached from the branch and falls.

A and B are two objects with mass 6 kg and 34 kg respectively. Then

physics force and newton's laws of motion concept of inertia galileo's law and inertia mass and inertia

  1. A has more inertia than B

  2. B has more inertia than A

  3. A and B both have same inertia

  4. none of the above is true

Show answer
Correct Option: B
Explanation:

Inertia has direct dependence on $mass$. More is the mass of the body, more is the inertia.

Since, B has more mass, thus B has more inertia than A. 

P and Q are two objects with masses 5 kg and 30 kg respectively. Then

physics force and newton's laws of motion concept of inertia galileo's law and inertia mass and inertia

  1. P has more inertia than Q

  2. Q has move inertia than P

  3. P and Q have the same inertia

  4. neither P nor Q has any inertia

Show answer
Correct Option: B
Explanation:

Inertia has direct dependence on $mass$ of the body. More the mass of the body, more will be its inertia.

Since Q has more mass, thus Q has more inertia than P.

Why can dust be removed from a carpet by shaking it, or by beating it with a stick?

physics force and newton's laws of motion concept of inertia galileo's law and inertia mass and inertia

  1. Because of inertia of rest

  2. Because of inertia of motion

  3. Because of inertia of direction

  4. Because of momentum

Show answer
Correct Option: A
Explanation:

When the carpet is shaken or beaten by a stick, then the carpet moves back but the dust remains still due to inertia of rest and hence the dust particles get separated out.

Which will have move inertia?

physics force and newton's laws of motion concept of inertia galileo's law and inertia mass and inertia

  1. A plastic eraser

  2. Pencil

  3. A book

  4. A table

Show answer
Correct Option: D
Explanation:

The object having the greatest mass has the greatest inertia.

As the the table is the heaviest object among the given options, thus table will have more inertia.