Force and Laws of Motion
Frequently Asked Questions
Force is a push or pull on an object that can change its state of motion or shape.
Balanced forces are equal in magnitude and opposite in direction, producing no change in motion.
Unbalanced forces cause a change in the state of motion or shape of an object.
Sir Isaac Newton formulated the three laws of motion.
An object remains at rest or in uniform motion unless acted upon by an unbalanced external force.
Inertia is the tendency of an object to resist any change in its state of motion or rest.
The rate of change of momentum is directly proportional to the applied force and occurs in its direction.
For every action, there is an equal and opposite reaction.
Momentum is the product of an object’s mass and velocity, given byp=m×vp = m \times vp=m×v.
The SI unit of force is the newton (N).
The SI unit of momentum is kg·m/s.
One newton is the force that produces an acceleration of 1 m/s² in an object of mass 1 kg.
F=m×aF = m \times aF=m×a— whereFFFis force,mmmis mass, andaaais acceleration.
Acceleration depends directly on the applied force and inversely on the object’s mass.
Due to inertia, the passenger's body resists the forward motion.
Due to inertia of motion, the upper part of the passenger’s body continues moving forward.
Running increases momentum, helping them cover a greater distance.
Force is directly proportional to acceleration (F?aF ? aF?a).
The forces balance each other, and the object remains in uniform motion or rest.
The total momentum of a system remains constant when no external force acts on it.
When a gun is fired, the bullet moves forward, and the gun recoils backward with equal momentum.
Total momentum before and after collision remains equal if no external force acts.
Action and reaction are equal in magnitude, opposite in direction, and act on different bodies.
Mass is the amount of matter in an object and a measure of its inertia.
The SI unit of mass is kilogram (kg).
It is the rate of change of velocity when a force is applied to a body.
A heavy object has greater mass, so it resists changes in motion more.
F=m×aF = m \times aF=m×a, showing that force causes acceleration depending on mass.
Due to conservation of momentum; bullet and gun move in opposite directions.
When we walk, our foot pushes the ground backward, and the ground pushes us forward.
Momentum depends on mass and velocity of the object.
A large force acting for a short time, such as in collisions or explosions.
Impulse is the product of force and time, equal to the change in momentum.
The SI unit of impulse is newton-second (N·s).
Momentum is zero when either mass or velocity is zero.
By increasing its velocity or mass.
A lighter body has less mass and hence less inertia.
Motion in which an object covers equal distances in equal time intervals in a straight line.
Acceleration decreases as mass increases (a?1/ma ? 1/ma?1/m).
It is also known as the Law of Acceleration.
Zero, as velocity is zero.
Sand increases the time of impact, reducing the effect of the force on landing.
By expelling gases downward, which push the rocket upward due to action-reaction pairs.
To reduce pressure and distribute weight evenly for stability.
Kicking a football causes it to move due to an unbalanced force.
Airbags increase the time of impact during collisions, reducing force and injuries.
Retardation or negative acceleration occurs when velocity decreases with time.
Due to opposing frictional force between the object and the surface.
Force equals the rate of change of momentum (F=?p?tF = \frac{?p}{?t}F=?t?p).
They are known as the fundamental laws describing motion and dynamics of objects.
