Force and Laws of Motion Complete Chapter🔥| CLASS 9th Science| NCERT covered | Prashant Kirad

Exphub 9th &10th・2 minutes read

Prashant Bhaiya demonstrates a physics magic trick emphasizing the study of Force and Law of Motion, promising to cover related theory and questions in the future. Examples and explanations illustrate concepts like balanced and unbalanced forces, momentum, and Newton's Laws, stressing the importance of understanding these principles for effective learning and practical applications.

Insights

Prashant Bhaiya introduces a magic trick with a glass, paper, and a coin of ₹1, emphasizing the importance of studying Force and Law of Motion.
Objects move at a constant speed due to balanced forces, while unbalanced forces lead to speed changes and motion alterations.
Newton's Laws of Motion, including the concept of inertia, momentum, and force, are crucial in understanding various physical phenomena and practical applications in everyday scenarios.

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Recent questions

What is the definition of force?
Force is a push or pull.
How do balanced forces affect motion?
Balanced forces maintain constant speed.
What is the significance of inertia?
Inertia resists changes in rest or motion.
How is momentum calculated?
Momentum is mass multiplied by velocity.
What does Newton's Third Law state?
Newton's Third Law involves equal and opposite reactions.

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Summary

00:00

Force and Motion: Physics Magic Trick Explained

Prashant Bhaiya introduces a magic trick with a glass, paper, and a coin of ₹1.
Demonstrates a physics concept through the magic trick, emphasizing the importance of studying Force and Law of Motion.
Promises to cover theory and questions related to the topic in the upcoming lecture.
Encourages students to maintain high energy levels for effective learning.
Defines force as a push or pull, distinguishing between scalar and vector quantities.
Explains the SI unit of force as Newton and mentions the unit Dyne.
Details the ability of force to move stationary objects, stop moving bodies, change direction, speed, and shape or size of objects.
Introduces the concept of balanced and unbalanced forces using examples of equal and unequal forces acting on objects.
Emphasizes that objects move at a constant speed due to balanced forces and speed changes with unbalanced forces.
Provides examples of questions related to finding the net force in diagrams with different force values.

11:38

"Balanced forces prevent motion changes effectively"

Understanding tough questions leads to solving them effectively.
Balanced forces result in a net force of zero, while unbalanced forces cause motion changes.
Balanced forces maintain uniform motion without altering it.
Unbalanced forces lead to changes in motion.
Balanced forces do not accelerate bodies.
Acceleration is zero in balanced forces.
Balanced forces have equal and opposite magnitudes.
Bodies resist changes in rest or motion due to inertia.
Inertia of rest and motion explain why objects stay at rest or in motion.
Seat belts in vehicles prevent injuries by countering inertia.

23:38

Forces, Inertia, and Momentum Explained Simply

Water droplets fall due to gravity when a towel is given velocity.
The question of why clothes get wet when water spills is explained by the concept of inertia.
The head of a hammer tightens when force is applied to the handle.
The bottom coin moves when a pile of coins is hit due to inertia.
The concept of inertia is illustrated through examples like a football and a rock.
Newton's First Law of Motion states that a body remains in rest or uniform motion unless an external force is applied.
Momentum is explained as the product of mass and velocity, with examples like a small bullet causing harm due to high momentum.
Impulse is defined as force multiplied by time, affecting the rate of change of momentum.
Momentum calculations are demonstrated with examples involving mass and velocity.
Newton's Second Law of Motion emphasizes the relationship between force and the rate of change of momentum.

36:35

"Force, Time, and Momentum: Newton's Laws"

The rate of change of momentum of an object is directly proportional to the applied unbalanced force in the direction of force.
Newton Baba stated that changes in momentum are directly proportional to external force.
The formula for change in momentum per unit time is delta p/delta t.
Change in momentum per unit time is equal to acceleration, with the formula delta v/t.
Newton Baba emphasized that changes in momentum per unit time are directly proportional to external force.
The formula for force is mass multiplied by acceleration.
Force depends on mass and acceleration.
Time plays a crucial role in the impact of force on an object.
The concept of time affecting force is illustrated through examples of falling objects.
Understanding the formula for change in momentum by time is essential in explaining various scenarios, such as injuries from falling objects.

50:10

Physics of Force: Impact and Reduction Techniques

The bed moved on its own after you hit it, causing confusion in your family during your childhood.
Understanding why a fast-moving cricket ball hurts more than a slower one involves the concepts of velocity, mass, and momentum.
Cricketers move their hands back when catching a ball to reduce the force of impact and minimize pain.
The force formula is crucial, with force equaling mass multiplied by acceleration.
One newton is defined as the force applied on a body with a mass of 1 kg experiencing an acceleration of 1 meter per second squared.
Doubling the mass of a body halves the acceleration, while halving the acceleration halves the force.
Fielders pull their hands back when catching to reduce the force of impact and minimize pain.
Athletes in high jump events land on cushions or sand to reduce the force of impact by increasing the time of impact.
Karate players use quick, powerful strikes to break slabs of ice to minimize the force of impact and reduce pain.
Analyzing a velocity-time graph helps determine the force acting on a body at different points based on acceleration and velocity changes.

01:02:41

"Calculating Mass, Acceleration, and Newton's Laws"

The text discusses calculating the mass of the body in 10 seconds, emphasizing the urgency of the task.
It delves into the concept of acceleration, force, and mass, providing a step-by-step explanation of how to find acceleration using numerical values.
The importance of waking up early to catch a flight is highlighted, with a focus on the significance of time management.
The text transitions to explaining Newton's Third Law of Motion, detailing the principle of equal and opposite reactions to actions.
Practical examples are given to illustrate the application of Newton's Third Law, such as why both players get hurt when colliding in sports.
The text further explains the concept of force and momentum, emphasizing the direction and impact of forces on objects.
It explores the difficulty of walking on ice due to reduced friction, providing a practical example to illustrate the concept.
The phenomenon of gun recoil when firing a bullet is explained through the lens of Newton's Third Law, highlighting the equal and opposite reaction.
The text concludes with examples of how Newton's Third Law applies in various scenarios, such as swimming and rocket propulsion.
Practical demonstrations are used to elucidate the concept, like pushing water backward to move forward in swimming and the propulsion of a rocket using gas release.

01:14:37

Physics Exam: Forces, Momentum, and Inertia

Questions in an exam are numerous and need to be solved.
Understanding the reasons behind physical phenomena like friction and inertia is crucial.
Friction on the ground affects the movement of a spinning ball.
The force of attraction between the Earth and the Moon affects their movements.
Calculating force involves mass and acceleration, with conversions to kilograms.
Increasing mass and reducing velocity can impact the depth of penetration of a bullet.
Identifying physical quantities and their corresponding units, like force and acceleration.
Calculating momentum involves mass and velocity changes over time.
Understanding the change in momentum and calculating force when catching a moving object.
The concept of inertia plays a role in an athlete's ability to perform a long jump.

01:27:25

Understanding inertia through jumping with momentum.

The concept of inertia is explained through the example of a person jumping with momentum, showcasing how the body's tendency to keep moving forward is influenced by force and the laws of motion. Understanding these principles is crucial for children to grasp the physics concepts effectively.

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