Mastering Physics : Laws of Motion

Explore how force changes motion or shape, including speed, direction, and deformation, with practical examples. Learn inertia as the tendency to resist motion changes, illustrated by rest and motion cases.

Explore how inertia, tied to mass, resists starting or stopping motion. Define linear momentum as mass times velocity, a frame-dependent vector, and summarize Newton's laws: inertia, F=ma, and action-reaction.

Explore inertia and Newton's first law, showing zero acceleration yields constant velocity; analyze inertial frames and motion's resistance to change, then introduce Newton's second law F=ma.

Explains Newton's third law using table and object examples, outlining action-reaction pairs with gravity, normal forces, and friction, and shows how walking involves pushing the earth backward to move forward.

Stop a car moving at 40 km/h by applying braking with constant deceleration, calculate acceleration from final velocity zero, convert units, and determine the stopping force.

The lesson analyzes a horse and cart as two objects, showing how the horse pushes the ground backward to create forward force, aided by friction and normal forces, yielding acceleration.

Learn how equilibrium of forces occurs when the net force is zero, with three forces balanced that form a closed triangle; use the sine rule to relate magnitudes and angles.

Apply Lami's theorem to a mass suspended by two strings at 53° and 37°, balancing three forces—the two tensions and weight—to find the string tensions.

Explore how contact forces arise between objects, detailing normal force perpendicular to surfaces that balances weight, and friction that acts parallel to surfaces to resist motion.

Analyze spring force, where an external pull or push produces an equal and opposite reaction, with force proportional to the extension or compression via the spring constant.

Analyze forces on two suspended masses, identify upward and downward tensions, apply equilibrium to relate tensions to weights, and explain how the lower rope supports both masses.

Explore how the normal forces from two planes at 30 and 45 degrees balance to place a ball in equilibrium, using free-body diagrams and force components.

Identify the object and all forces, draw a free body diagram, choose axes along the motion, resolve forces, and solve for acceleration and normal forces in multi-object systems.

Analyze a two-block contact system where the experimenter pushes from behind to produce horizontal acceleration, identifying the external force and the internal contact force between blocks.

Examine how buoyancy, weight, and drag oppose velocity to yield constant ascent or descent, and calculate how much mass to remove for the balloon to rise at constant velocity.

Calculate the initial acceleration when a negative force acts on a point with a displacement of 220 cm and a 20 cm reference, yielding 10 m/s².

Analyze a frictionless two-block system with a horizontal push on the lower block; the upper block separates, and find time for it to cover 20 cm relative to lower block.

Analyze the tension along a uniformly massed rod in acceleration, deriving a linear tension profile from left to right and identifying the internal reaction forces via free body diagrams.

Solve a two-block pulley problem on inclined planes (53° and 37°) by drawing free-body diagrams, resolving gravity along the inclines, and determining the common acceleration from tension.

Analyze a two-mass pulley with masses M1 and M2, derive the acceleration from Newton's laws and tension, determine which mass descends, and examine the motion after the string breaks.

Analyze a 15 kg monkey on a rope fixed to ceiling, accelerating upward at 1 m/s^2 over 5 m, yielding about 165 newtons of tension and 3.16 s climb time.

Identify what constitutes a constraint, then derive the constraint relation for a pulley system where x1 plus x2 equals the string length, and differentiate to get velocity and acceleration relations.

Derive velocity relations in a two-dimensional constraint by differentiating the rope length, comparing velocity components along the string, and using fixed rope length to relate motions.

Analyze the constraint relation for a rigid rod between two smooth vertical walls in 2d. Derive velocity components along the rod and the center velocity, linking x and y coordinates.

Relate velocity of two masses connected by a string in a 2-d constraint problem by decomposing velocities along 37 and 53 degrees and equating them to find the second speed.

Apply Newton's law to a two-mass pulley system, using the constraint relation to show the two masses share the same acceleration and solving for tension with coupled equations.

The lecture derives a constraint relation between the accelerations of two blocks in a frictionless pulley system and sets up energy and force equations to solve for motion.

Examine constraint relations in a two-block pulley system and derive acceleration links from string length. Apply Newton's laws to compute tensions and motion directions.

Explore the constraint relation in a two-mass pulley problem, deriving accelerations from the masses, tensions, and gravity, and examining the normal balance and energy considerations.

Derive the acceleration in a pulley system using the string constraint and the forces on connected masses. Analyze tensions and directions to explain the upward and downward motion.

Analyze tensions in the string after cutting and determine accelerations of the connected blocks, considering upward and downward forces and spring compression, which may yield zero acceleration.

Learn about pseudo force in accelerated frames, illustrated by a bus, bike, car turns, and lift, showing a not real, fictitious backward force proportional to mass and acceleration.

Examine how vertical elevator acceleration creates a pseudo force, altering the apparent weight from 60 N to 72 N and affecting the normal force.

Analyze a block on a frictionless incline inside an elevator moving up with uniform velocity and with upward acceleration, deriving time to slide using mg components and pseudo forces.

Explore how a block on an accelerating horizontal plate experiences normal force, using plate-frame and ground-frame views, highlighting horizontal pseudo force and gravity in motion.

Explore how a moving incline creates a pseudo force on a block. Determine the acceleration that keeps the block stationary and the resulting normal force.

Examine static, sliding, and rolling friction, including maximum static friction. Learn how friction relates to normal force, surface, and area of contact, and define the angle of friction.

Examine a sliding object decelerating under friction opposing forward motion, with weight and normal forces balancing vertically, and friction equals mu times normal acting horizontally.

Understand static friction and the maximum limiting friction mu_s N, and see why the actual friction equals the external force. When no horizontal external force acts, friction is zero.

A block on a rough horizontal road decelerates under friction μ = 0.1; with normal equals weight and v² = u² + 2 a s, it stops after 50 m.

Analyze forces on an inclined plane to calculate the external force needed to move the body up or down, accounting for friction, gravity, and the normal force.

Resolve forces on a block on a rough 30-degree incline to find the horizontal force needed to move it up, accounting for gravity, friction, and the normal force.

explore a pulley problem with blocks on rough surfaces, deriving acceleration and tensions by applying gravity, friction, and normal forces to the system and solving multiple equations.

Apply the short cut technique for pulley problems using a common acceleration magnitude and net pulling force divided by total moving masses, with examples on connected masses and inclines.

Derive the three-mass pulley problem on a rough surface by writing equations for tensions, friction, and normal forces to determine the system's acceleration.

Limit horizontal acceleration with ground friction: a_max = μ g, regardless of applied force; analyze accelerating to cover distance and stopping under maximum deceleration μ g.

two blocks slide down a rough incline while connected; we determine system’s acceleration with friction and normal forces, and the internal reaction is zero when friction is equal.

Analyze a two-object system under applied force to compute the combined acceleration using total force over total mass, then verify feasibility by comparing with maximum friction.

examine a three-block system under external pulls, compare forces to maximum static friction, and determine whether blocks move together or slide, yielding a 5/6 m/s^2 acceleration for the combined motion.

Analyze a two-block system with a string, examining friction, tension, and normal force equal to mg as a horizontal force acts, to determine maximum friction and acceleration.

pulling the upper block creates backward friction on the block and the table, while static friction from the floor balances the force, keeping the heavy table stationary.