Tag: physics

Questions Related to physics

What will be the momentum of a stone having mass of $10\ kg$ when it is thrown with a velocity of $2\ m/s$?

physics force and newton's laws of motion momentum (p) introduction to momentum linear momentum

  1. $30\ kg\ m/s$

  2. $5\ kg\ m/s$

  3. $2.5\ kg\ m/s$

  4. $20\ kg\ m/s$

Show answer
Correct Option: D
Explanation:

Given :    $m = 10$ kg                   $v =2$ m/s

Thus momentum of a stone         $P = mv = 10\times 2 =20$  $kg$ $m/s$

Calculate the momentum of a bullet of $25\ g$ when it is fired from a gun with a velocity of $100\ m/s$:

physics force and newton's laws of motion momentum (p) introduction to momentum linear momentum

  1. $20\ kg\ m/s$

  2. $2500\ kg\ m/s$

  3. $2.5\ kg\ m/s$

  4. None

Show answer
Correct Option: C
Explanation:

Given :    $m =25$ g $= 0.025$ kg                   $v =100$ m/s

Thus momentum of the bullet         $P = mv = 0.025\times 100 =2.5$  $kg$ $m/s$

When a bullet is fired from a rifle its momentum become $20\ kg\ m/s$. If the velocity of the bullet is $1000\ m/s$ what will be its mass?

physics force and newton's laws of motion momentum (p) introduction to momentum linear momentum

  1. $30\ g$

  2. $5\ kg$

  3. $20\ g$

  4. $500\ g$

Show answer
Correct Option: C
Explanation:

Given :    $P = 20$  $kg$ $m/s$                    $v = 1000$  $m/s$

$\therefore$ Mass of bullet       $m = \dfrac{P}{v} = \dfrac{20}{1000} = 0.02$ kg  $ = 20$ g

A car having mass of $1000\ kg$ is moving with a velocity of $0.5\ m/s$. What will be its momentum?

physics force and newton's laws of motion momentum (p) introduction to momentum linear momentum

  1. $400\ kg\ m/s$

  2. $200\ kg\ m/s$

  3. $500\ kg\ m/s$

  4. $0.05\ kg\ m/s$

Show answer
Correct Option: C
Explanation:

Given :    $m = 1000$ kg                   $v =0.5$ m/s

$\therefore$  Momentum of the car         $P = mv = 1000\times 0.5 =500$  $kg$ $m/s$

A stone attains a momentum of $1\ kg\ m/s$ when it flies with a velocity of $2\ m/s$, then what will be the mass of the stone?

physics force and newton's laws of motion momentum (p) introduction to momentum linear momentum

  1. $500\ g$

  2. $2\ kg$

  3. $2\ g$

  4. None

Show answer
Correct Option: A
Explanation:

Given :    $P = 1$ $kg$ $m/s$                  $v =2$ m/s

Momentum of the stone        $P = mv$
$\therefore$  Mass of stone     $m = \dfrac{P}{v} =\dfrac{1}{2} = 0.5$ kg  $=500$ g

The mass of a goods lorry is $4000\ kg$ and the mass of goods loaded on it is $20000\ kg$. If the lorry is moving with a velocity of $2\ m/s$ what will be its momentum?

physics force and newton's laws of motion momentum (p) introduction to momentum linear momentum

  1. $48000\ kg\ m/s$

  2. $48\ kg\ m/s$

  3. $4.8\ kg\ m/s$

  4. None

Show answer
Correct Option: A
Explanation:

Given :    $m _1 = 4000$ kg           $m _2  =20000$ kg             $v =2$ m/s

Total mass of the 'lorry + goods' system      $M = 4000+20000 =24000$ kg
$\therefore$ Total momentum of the system        $P = Mv = 24000\times 2 =48000$  $kg$ $m/s$

The momentum of a toy bus of $0.01\ kg$ moving with a velocity of $5\ m/s$ is:

physics force and newton's laws of motion momentum (p) introduction to momentum linear momentum

  1. $0.005\ kg\ m/s$

  2. $0.05\ kg\ m/s$

  3. $0.005\ N\ s$

  4. $0.5\ kg\ m/s$

Show answer
Correct Option: B
Explanation:

Given :   $m =0.01$ kg           $v = 5$ m/s

Momentum of the toy         $P = mv  = 0.01\times 5 = 0.05$  $kg$ $m/s$

What does the principle of conservation of linear momentum state?

physics force and newton's laws of motion momentum (p) introduction to momentum linear momentum

  1. The linear momentum of a system cannot be changed.

  2. The linear momentum of a system cannot remain constant.

  3. The linear momentum of a system can be changed only if internal forces act.

  4. The linear momentum of a system can be changed only if external forces acts on it.

Show answer
Correct Option: D
Explanation:

The principle of conservation of linear momentum states that the linear momentum of a system can be changed only if external forces acts on it.

Which of the following balls is easier to catch even though all of them are moving with the same velocity?

physics force and newton's laws of motion momentum (p) introduction to momentum linear momentum

  1. Tennis ball

  2. Cricket ball

  3. Basket ball

  4. Both cricket and basket ball

Show answer
Correct Option: A
Explanation:
Tennis ball is lighter in weight as compare to cricket ball and thus has momentum much less than the momentum of cricket ball and basket ball ( momentum is equal to mass × velocity)
body that has large momentum possesses large impact as well thus cricket ball,basket ball having more momentum than tennis ball even if they move with same velocities causes more impact on the hands of person that tends to catch it and might sometimes get hurt thus it is easy to catch a tennis ball because its momentum is less  so is its impact

A force acts on a body of mass 3 kg such that its velocity changes from 4 m $s^{-1}$ to 10 m $s^{-1}$.Calculate the change in the momentum of the body.

physics force and newton's laws of motion momentum (p) introduction to momentum linear momentum

  1. 2 kg m $s^{-1}$

  2. 14 kg m $s^{-1}$

  3. 18 kg m $s^{-1}$

  4. 42 kg m $s^{-1}$

Show answer
Correct Option: C
Explanation:

A force acts on a body of mass 3 kg such that its velocity changes from 4 m/s to 10 m/s

change in momentum 
$\Delta p=m(v _1-v _2)=3*(10-4)=18kg m/s$