Net Force

Q.

What is a null vector example?

Q.

What happens when two forces act in the same direction?

Q.

What is net force???

Q.

Two persons are applying forces on two opposite sides of a moving cart. The cart still moves at the same speed in the same direction. What do you infer about the magnitudes and direction of the forces applied?

Q. Explain the second law of motion.

Q. If the net force acting on an object is not zero, then which of the following is/are the possible consequence(s)?

1. The object has uniform velocity
2. The object is accelerating
3. The object is decelerating
4. The object is static

Q.

When the net force acting on an object is zero, the total momentum of the system will

1. remain constant

2. increase with time

3. decrease with time

4. None of these

Q.

If a body is in equilibrium under a set of non-collinear forces, then the minimum number of forces has to be

1. Four

2. Three

3. Two

4. Five

Q. The net force acting on a body of mass 1 kg moving with a uniform velocity of $5m{s}^{-1}$ is:

1. 0 N
2. 5 N
3. 10 N
4. 50 N

Q.

What is the meaning of net external force?

Q.

When an object undergoes acceleration

1. its speed always increases

2. its speed always increases

3. a force always acts on it

4. the force may be zero

Q. According to the third law of motion when we push on an object, the object pushes back on us with an equal and opposite force. If the object is a massive truck parked along the roadside, it will probably not move. A student justifies this by answering that the two opposite and equal forces cancel each other. Comment on this logic and explain why the truck does not move.

Q. What is the cumulative effect of the force?

Q.

A body is accelerating in a straight line. The unbalanced force acts:

1. In the direction of motion of the body.

2. In the direction perpendicular to the motion of the body.

3. In the direction opposite to the motion of the body.

4. None of these.

Q.

What is the net force acting on the block?

1. 5 N
2. 10 N
3. 0 N
4. None of the above

Q. What is the magnitude of net force in the given situation?

1. $5N$
2. $0.5N$
3. $1N$
4. $2N$

Q.

What is the magnitude and direction of the resultant of 4 coplanar forces as follows:

F_{​​​​​​1} vector = 20 N Due East

F_{​​​​​​2} vector = 40 N due West

F_{​​​​​3} vector = 50√2 N due north west

F_{​​​​​4} vector = 20√2 N due south west

Q. ntTwo masses 5 Kg nd 3 Kg are suspended from the ends of an unstretchable light string pasing over a frictionless pulley. When the masses are released, the thrust on the pully is (g = 10 mis-2).n

Q.

A block kept at rest on a horizontal table is pushed by two horizontal forces, one towards north and other towards south, which are equal in magnitude. What can be said about the motion of the block?

1. The block will move towards east.
2. The block will move towards west.
3. The block will move upwards.
4. The block will remain stationary.

Q. Newton’s laws do not hold true in the inertial frame of reference.

1. True
2. False

Q. What is the magnitude of the net force acting on the box?

1. $5N$
2. $10N$
3. $0N$
4. $15N$

Q. Question 1 (b)
The following is the distance-time table of an object in motion:
$\begin{array}{cc}Timeinseconds& Distanceinmetres\\ 0& 0\\ 1& 1\\ 2& 8\\ 3& 27\\ 4& 64\\ 5& 125\\ 6& 216\\ 7& 343\end{array}$
(b) What do you infer about the forces acting on the object?

Q.

If a body is at rest, it means no force is acting on it

1. True

2. False

Q.

• Question 7: A body of weing W is suspended from the ceiling of a room through a rope of weight R. the ceiling pulls the rope by a force of

Q.

When two equal and opposite forces act at the same point, then the resultant force is double that of either of the forces

1. True
2. False

Q. Question 3
A hammer of mass 500 g, moving at $50m{s}^{-1}$, strikes a nail. The nail stops the hammer in a very short time of 0.01 s. What is the force of the nail on the hammer?

Q. A block of mass m is placed on a rough inclined plane of inclination θ. Its downward motion can be just prevented by applying an upward pull force F, parallel to the plane and it can be made to just slide upward by applying a force 3F, parallel to the plane. The coefficient of friction between the block and the inclined plane is

m द्रव्यमान के एक गुटके को θ आनति के खुरदरे आनत तल पर रखा जाता है। इसकी नीचे की ओर गति को तल के समान्तर ऊपर की ओर खिंचाव बल F आरोपित करके ठीक रोका जा सकता है तथा तल के समान्तर 3F बल आरोपित करके इसे ठीक ऊपर की ओर सरकाया जा सकता है। गुटके तथा आनत तल के मध्य घर्षण गुणांक है

1. $\frac{\tan \theta }{2}$
2. $\frac{\tan \theta }{3}$
3. $\frac{\tan \theta }{4}$
4. 3 tanθ

Q.

What is the magnitude of the net force acting on the box?

1. 5 N
2. 0 N
3. 10 N
4. 15 N

Q.

A body of mass 2 kg is moving on a smooth floor in straight line with a uniform velocity of 10 m/s. Resultant force acting on the body is:

1. 20N

2. 10N

3. 2N

4. zero

Q.

Two identical wooden blocks are tied one behind the other and pulled across a rough horizontal surface with the help of a horizontal force. If the force required to pull them at constant speed is F, and if we attach the block one over the other, the new force required to pull the blocks with constant speed is ___