- Newton's First Law of Motion: Also known as the Law of Inertia, it states that an object will remain at rest or in uniform motion in a straight line unless acted upon by an external force.
- Inertia: The tendency of an object to resist changes in its state of motion is called inertia.
- Newton's Second Law of Motion: The force acting on an object is equal to the rate of change of its momentum, expressed as F = ma, where F is force, m is mass, and a is acceleration.
- Momentum: Defined as the product of an object's mass and velocity, expressed as p = mv.
- SI Unit of Force: The unit of force is the Newton (N), where 1 N = 1 kg·m/s².
- Newton's Third Law of Motion: For every action, there is an equal and opposite reaction.
- Action-Reaction Forces: These forces act on different objects and are equal in magnitude but opposite in direction.
- Free Body Diagram: A diagram that represents all the forces acting on an object.
- Net Force: The vector sum of all forces acting on an object determines its acceleration.
- Friction: A force that opposes the relative motion between two surfaces in contact.
- Static Friction: The frictional force that prevents an object from moving when a force is applied.
- Kinetic Friction: The frictional force acting on an object in motion.
- Centripetal Force: The force that keeps an object moving in a circular path, directed toward the center of the circle.
- Weight: The force of gravity acting on an object's mass, expressed as W = mg.
- Normal Force: The force exerted by a surface perpendicular to the object resting on it.
- Balanced Forces: Forces that are equal in magnitude and opposite in direction, resulting in no net force and no acceleration.
- Unbalanced Forces: Forces that cause a change in an object's motion due to a net force.
- Linear Momentum Conservation: In an isolated system, the total momentum remains constant if no external force acts on it.
- Impulse: The change in momentum of an object, expressed as Impulse = Force × Time.
- Applications: Newton's laws are fundamental in explaining motions in daily life, engineering, and space exploration.
- Examples of First Law: A stationary ball remains at rest until kicked; a car in motion continues unless brakes are applied.
- Examples of Second Law: Heavier objects require more force to accelerate compared to lighter ones.
- Examples of Third Law: A rocket launches as exhaust gases are expelled downward, creating an upward thrust.
- Inertial Frame of Reference: A frame of reference where Newton's laws are applicable without corrections.
- Non-Inertial Frame of Reference: A frame of reference undergoing acceleration where fictitious forces appear.
- Equilibrium Condition: When the net force and net torque on an object are zero, it is in equilibrium.
- Applications in Sports: Newton's laws explain motions in games like football, cricket, and gymnastics.
- Inclined Plane: Newton's laws help calculate forces acting on objects on slopes.
- Rocket Propulsion: Based on the principle of conservation of momentum and Newton's Third Law.
- Harmonic Motion: Explains forces in oscillatory systems like pendulums and springs.
- Force Diagrams: Help visualize and calculate forces acting on systems in mechanical problems.
- Gravitational Force: The force of attraction between two masses, proportional to their product and inversely proportional to the square of their separation.
- Applications in Engineering: Newton's laws guide the design of structures, vehicles, and machinery.
- Projectile Motion: Combines Newton's laws with kinematics to describe the path of objects under gravity.
- Friction Coefficients: Quantify the extent of frictional forces between surfaces.
- Terminal Velocity: The constant speed attained by an object when forces of gravity and air resistance balance.
- Drag Force: A resistive force exerted by a fluid on a moving object.
- Spring Force: Described by Hooke's Law, F = -kx, where k is the spring constant, and x is the displacement.
- Tension Force: The force transmitted through a string, rope, or cable when pulled tight.
- Rotational Dynamics: Newton's laws extend to rotating systems with concepts of torque and angular momentum.
- Space Exploration: Newton's laws are critical in orbital mechanics and spacecraft trajectories.
- Newton's Law of Gravitation: Explains the universal attractive force between masses.
- Practical Implications: Newton's laws form the basis for various technologies, from transportation to robotics.
Questions
- Who formulated the three laws of motion?
- What does Newton’s First Law of Motion state?
- What is inertia?
- Which law explains why a passenger leans forward when a car suddenly stops?
- What is the SI unit of force?
- Which of the following is an example of Newton’s Third Law?
- What is the mathematical expression for Newton’s Second Law?
- What is the net force on a body moving with constant velocity?
- When a book is at rest on a table, which forces are acting on it?
- Which force keeps planets in orbit around the Sun?
- What happens to acceleration if the mass of an object increases for a constant force?
- Action and reaction forces are always:
- What is the acceleration due to gravity on Earth?
- A car traveling at constant speed is an example of which Newton's Law?
- If a force of 10 N acts on a 2 kg object, what is its acceleration?
- What type of force opposes the motion of objects?
- Which of the following is true for balanced forces?
- What force is needed to accelerate a 5 kg object at 2 m/s²?
- What happens to momentum if the mass of an object is doubled but velocity remains constant?
- Why does a ball thrown vertically upwards return to the ground?
- If an object is in equilibrium, which of the following is true?
- What is the reaction force when you push against a wall?
- What happens to an object in free fall in a vacuum?
- Why do rockets move in space?
- What determines the magnitude of acceleration of an object?
- Why does a person fall backward when a bus starts suddenly?
- What happens to acceleration if the force applied on an object is doubled?
- What is the weight of a 50 kg object on Earth?
- A parachutist reaches terminal velocity when:
- Which of the following is not an example of Newton's Laws of Motion?