Author Archives: George Tafari

THE STOCK MARKET: When a Put Option Contract Goes South ( Which is Good )

CHECK THIS OUT!!! This is the buying side of the game, and the maximum loss is the purchase cost of the contract ( $95.00 in this case ). An SPY ( S and P 500 Index ) put option was purchased. Each contract is worth $0.95, but options contracts are sold in groups of 100;Continue reading “THE STOCK MARKET: When a Put Option Contract Goes South ( Which is Good )”

KINEMATICS: Total Time of Flight for a Projectile

Q: A model-rocket club is standing at the edge of a 40.0 m building. They arrange a launcher so that it is off the cliff’s edge, and they launch a rocket straight upward at an initial velocity ( v ) of 380.0 m/s. Neglecting wind resistance, how long will it take for the rocket toContinue reading “KINEMATICS: Total Time of Flight for a Projectile”

AP PHYSICS: Rotational Kinematics

Q: A 25.0 kg grindstone disc with a 0.250 m radius ( r ) rotates with an angular speed ( ω ) of 30.0 rad/s. When power to the disc is shut off, it decelerates and comes to rest over the course of 20.0 s. When the grindstone is shut off, a speck of dustContinue reading “AP PHYSICS: Rotational Kinematics”

AP PHYSICS: Final Speed of a Block / Incline System

Q1 : A mass ( m1 ) of 1.20 kg is situated at the bottom of an incline that is 30o to the horizontal. At the top of the incline, there’s a 0.500 kg disk that is kept fixed by a frictionless axle. A cord is placed over the disk and used to lift aContinue reading “AP PHYSICS: Final Speed of a Block / Incline System”

AP PHYSICS: Pulleys, Torque, Tension, and the Moment of Inertia

Two spherical bearings of mass ( m1 ) and ( m2 ) are attached by belt to a pulley that is situated between them. An electric motor is also attached to the pulley, and it is positioned between these masses. When the motor is turned on, the pulley provides 15.0 N of tension on theContinue reading “AP PHYSICS: Pulleys, Torque, Tension, and the Moment of Inertia”

ENERGY AND MOMENTUM: Conservation of Energy, Linear Momentum, and Angular Momentum During a Collision

1. Momentum is always conserved when collisions occur. Momentum is defined as being a quantity of motion, and it is a product of mass and velocity. A small object travelling with a high velocity has great momentum ( Ex. A bullet ), and a massive object travelling with a low velocity has great momentum (Continue reading “ENERGY AND MOMENTUM: Conservation of Energy, Linear Momentum, and Angular Momentum During a Collision”

EQUILIBRIUM STATICS: Stationary and Moving Center of Mass Derivation

In physics, concepts like force, energy, and motion go hand-in-hand with one another. An unbalanced force will cause an object to accelerate. Equal and opposite force pairs will cause an object to remain at rest or maintain a constant velocity if it is already in motion. When an applied force causes an object or systemContinue reading “EQUILIBRIUM STATICS: Stationary and Moving Center of Mass Derivation”

STATIC EQUILIBRIUM: Concurrent Force Systems

A system that is acted upon by concurrent forces is in equilibrium when it remains motionless relative to an observer within the system’s frame of reference: In the diagram above, the system is a 200 N object that is suspended from a pulley. Since the system is not accelerating, we must search for forces thatContinue reading “STATIC EQUILIBRIUM: Concurrent Force Systems”

GAS LAWS: Boltzmann Constant Derivation

An ideal gas is a gas that behaves as if the only significant interactions between its atoms occurs during elastic collisions. Under ideal conditions, intramolecular force interactions due to charged particles, as well as systemic losses due to entropy, are ignored. In addition to these subatomic interactions occurring within a specified quantity of space, thereContinue reading “GAS LAWS: Boltzmann Constant Derivation”