Tag: concept of force and its unit

Questions Related to concept of force and its unit

A $5N$ force is applied from one direction on a body and at the same time same force is applied on it from the other side.So,what wil be the result

  1. Body will move towards left

  2. Body will move towards right

  3. Body will not move at all

  4. Body will start rolling at its place


Correct Option: C
Explanation:

In general, more than one force may be acting on an object.However,the effect on the object is due to the net force acting on it will be null.

$2N$ force is applied on a body from the right side and $6$ N is applied from the left side .The resultant force will be __________ N

  1. $8$

  2. $4$

  3. $3$

  4. None


Correct Option: B
Explanation:

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

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

  1. Change the speed of motion

  2. Change the direction of motion

  3. Both

  4. Change the magnitude of the motion 


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

  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.


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

  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


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

  1. Addition of two forces

  2. Difference of two forces

  3. Division of two forces

  4. Multiplication of two forces


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 

  1. At rest

  2. Moving with a uniform velocity

  3. In equilibrium

  4. Moving with an acceleration


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?

  1. First law of motion.

  2. Second law of motion.

  3. Third law of motion

  4. Law of conservation of energy.


Correct Option: A,B,C

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

  1. $1 kgf = 1N$

  2. $1 kgf = 0.98 N$

  3. $1 kgf = 9.8 N$

  4. $1 N= 9.8 kgf$


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.

  1. 1

  2. 2

  3. 3

  4. 4


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 $\displaystyle \propto\frac{1}{unit}$)