Tag: physics

Questions Related to physics

If force acts at an angle to the direction of motion,it can

physics force concept of force and its unit force - push or pull forces

  1. Change the speed of motion

  2. Change the direction of motion

  3. Both

  4. Change the magnitude of the motion 

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Correct Option: C
Explanation:

If the force acts at an angle to the direction of motion,it can change the speed as well as the direction of motion.

When two forces,applied on an object, equal and opposite,then the forces

physics force concept of force and its unit force - push or pull forces

  1. May move the object

  2. May stop the object

  3. May move the object and also cause a change in its shape

  4. Do not move the object but may cause a change in its shape.

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Correct Option: D
Explanation:

A force may not always succeed in bringing a change in the state of motion of an object.

When equal and opposite force is applied it do not let the body to move,but cause change in shape of the body.

When a small body hits a very large body,then the

physics force concept of force and its unit force - push or pull forces

  1. Forces acting on both the bodies are different in magnitude but direction is same.

  2. Forces acting on both the bodies are equal in magnitude and direction is also same

  3. Forces acting on both the bodies are equal in magnitude but opposite in direction

  4. Forces acting on both the bodies are different and directon is also opposite to each other

Show answer
Correct Option: C
Explanation:

When a small body hits a very large body,then the forces acting on both the bodies are equal in magnitude but opposite in direction.However the effect (of force)produced in the small body is very large as compared to the effect of (the equal)force on the larger body.

If two forces act in opposite directions on an object,the net force acting on it is the

physics force concept of force and its unit force - push or pull forces

  1. Addition of two forces

  2. Difference of two forces

  3. Division of two forces

  4. Multiplication of two forces

Show answer
Correct Option: B
Explanation:

Forces applied on an object in the same direction add to one another.

If two forces axt in the opposite directions on an object,the net force acting on it is the difference between the two forces

When three forces of 50N, 30N and 15N act on a body, then the body is 

physics force concept of force and its unit force - push or pull forces

  1. At rest

  2. Moving with a uniform velocity

  3. In equilibrium

  4. Moving with an acceleration

Show answer
Correct Option: D
Explanation:

Here all the three force will not keep the particle in equilibrium$,$

So$,$ the net force will not be zero and the part particle will move with an acceleration$.$
Hence,
option $(D)$ is correct answer.

Raj was riding his bicycle.After some time, he got tired and stopped paddling the cycle. The cycle stopped after traveling some distance.Which laws of motion helps us to explain this phenomenon?

physics force concept of force and its unit force - push or pull forces

  1. First law of motion.

  2. Second law of motion.

  3. Third law of motion

  4. Law of conservation of energy.

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Correct Option: A,B,C

The relation between the $S.I.$ unit of force and the weight of a $1 kg$ mass is : 

physics force concept of force and its unit force - push or pull forces

  1. $1 kgf = 1N$

  2. $1 kgf = 0.98 N$

  3. $1 kgf = 9.8 N$

  4. $1 N= 9.8 kgf$

Show answer
Correct Option: C
Explanation:

Answer is C.

The S.I. unit of force is Newton, the absolute unit of force in the International System of Units (SI units). It is defined as that force necessary to provide a mass of one kilogram with an acceleration of one metre per second per second.


S.I. unit of Force = $Mass(kg)\times Acceleration\quad due\quad to\quad Gravity(g)(9.8m/{ s }^{ 2 })$ = Newton

Force (Newton) = Mass x g 

For example, The weight (force) of a mass of 1 kg = 1 x 9.8 = 9.8 N

Hence, 1 kgf = 9.8 N

Force acting on a particle is 5 N. If the unit of length and time are doubled and unit of mass is halved then the numerical value of the force in the new unit will be ________ times the initial value.

physics force concept of force and its unit force - push or pull forces

  1. 1

  2. 2

  3. 3

  4. 4

Show answer
Correct Option: D
Explanation:

Force = $\displaystyle 5: : \frac{kg\times m}{sec^{2}}$
If unit of length and time are doubled and the unit of mass is halved
Then the unit of force will be $\displaystyle \left ( \frac{\frac{1}{2}\times 2}{(2)^{2}} \right )=\frac{1}{4}$ times
Hence the numerical value of the force will be 4 times (as numerical value $\displaystyle \propto\frac{1}{unit}$)

1 dyne is equal to

physics force concept of force and its unit force - push or pull forces

  1. 980 g wt

  2. $\displaystyle \frac{1}{980}$ g wt

  3. 980 kg wt

  4. none of these

Show answer
Correct Option: B
Explanation:

Dyne is unit of force specified in CGS system. 

So $ 1 dyne= 10^{-5} N $
And $ 1 N = \dfrac{1}{9.80} kg $
Now,
$ 1 dyne= \dfrac{1}{9.80} \times 10^{-5}  kg$


Changing kg into grams,
 $ 1 dyne = \dfrac{1}{9.80} \times 10^{-5}  \times 10^3 g $
So,
 $ 1 dyne= \dfrac{1}{980}g  \ wt $.

Which of the following sets of concurrent forces may be in equilibrium?

physics force concept of force and its unit force - push or pull forces

  1. $\displaystyle { F } _{ 1 }=3N,{ F } _{ 2 }=5N,{ F } _{ 3 }=1N$

  2. $\displaystyle { F } _{ 1 }=3N,{ F } _{ 2 }=5N,{ F } _{ 3 }=9N$

  3. $\displaystyle { F } _{ 1 }=3N,{ F } _{ 2 }=5N,{ F } _{ 3 }=6N$

  4. $\displaystyle { F } _{ 1 }=3N,{ F } _{ 2 }=5N,{ F } _{ 3 }=15N$

Show answer
Correct Option: C
Explanation:
"Forces are in equilibrium when vector sum of these three forces is zero and they form a triangle.
For a triangle, the sum of the two sides is always greater than the third side
Therefore, $F _1 = 3N; F _2 = 5N; F _3 = 6N$

$F _1 + F _2 > F _3$

$F _2 + F _3 > F _1$

$F _3 + F _1  > F _2$