Balanced and Unbalanced Forces Questions in English

(C) Force exerted by the engine,$F = 40000 \,N$.
Frictional force offered by the track,$F_f = 5000 \,N$.
The net accelerating force is the difference between the applied force and the opposing frictional force.
Net accelerating force,$F_a = F - F_f$.
$F_a = 40000 \,N - 5000 \,N = 35000 \,N$.
Hence,the net accelerating force is $35000 \,N$.

(C) When an object moves at a constant velocity,the net force acting on it is zero.
This means that the applied force must be perfectly balanced by the opposing frictional force.
Given that the applied horizontal force is $200\, N$,the frictional force must also be $200\, N$ in the opposite direction to maintain a constant velocity.
Therefore,the friction force exerted on the cabinet is $200\, N$.

(A) Yes,$I$ agree with Soni.
According to Newton's second law of motion,the acceleration $(a)$ of an object is directly proportional to the net force $(F_{net})$ acting on it,given by the formula $F_{net} = ma$,where $m$ is the mass of the object.
If several forces act on an object such that their vector sum (resultant force) is zero,then the net force $F_{net} = 0$.
Since $F_{net} = ma$,if $F_{net} = 0$ and $m \neq 0$,then $a = 0$.
Therefore,an object can have zero acceleration even when multiple forces are acting on it,provided they balance each other out.

(N/A) $(i)$ Force is an external push or pull that changes or tends to change the state of rest or uniform motion of a body in a straight line.
$(ii)$ Dyne is the absolute unit of force in the $CGS$ system. One dyne is defined as the force that produces an acceleration of $1 \ cm \ s^{-2}$ when acting on a body of mass $1 \ g$.
$(iii)$ Newton is the absolute unit of force in the $SI$ system. One newton is defined as the force that produces an acceleration of $1 \ m \ s^{-2}$ when acting on a body of mass $1 \ kg$.

(B) An object remains in its state of rest or uniform motion unless acted upon by an external unbalanced force.
According to Newton's first law of motion,an unbalanced force is required to change the state of rest or the state of uniform motion of an object.
Therefore,the force responsible for the change in position or state of an object is the unbalanced force.

$(FORCE)$ The physical quantity whose $SI$ unit is "newton" $(N)$ is force. Force is defined as a push or pull acting on an object, which can cause an object to accelerate, decelerate, or change its shape.

(C) When we stop pedalling a moving bicycle,it gradually slows down and eventually comes to a stop. This happens because of the force of friction acting between the road surface and the bicycle tyres. Friction is an unbalanced force that opposes the motion of the bicycle,causing it to decelerate.

(N/A) balanced force does not change the state of rest or motion of an object,but it may change the shape or size of the body.
$(b)$ An unbalanced force will change the state of rest of the object by producing acceleration in the direction of the applied force.

(A) The statement is $True$.
$A$ force is defined as a push or a pull acting on an object. While a force can cause an object to accelerate,change its speed,or change its direction,it does not always result in motion.
For example,if you push against a heavy wall,you are applying a force,but the wall does not move because the frictional force or the structural resistance balances your applied force. Therefore,force does not always produce motion in a body.

(D) force is a vector quantity. $A$ vector quantity is defined as a physical quantity that has both magnitude (size) and direction. Therefore,to completely describe a force,one must specify both how strong the push or pull is (magnitude) and the direction in which it is applied.

(B) According to Newton's $1^{st}$ Law of Motion,if the net external force acting on a body is zero (i.e.,balanced forces),the body will maintain its state of rest or uniform motion in a straight line.
Balanced forces do not change the state of motion of an object,meaning the acceleration of the body is zero.
Therefore,the body is either at rest or moving with a constant velocity.