Q: Consider a system in which a mass ( m1 = 6kg ) moves in the +x-direction at ( 2 m/s ) as a mass ( m2 = 2kg ) moves in the -x-direction at ( – 4 m/s ): How may we use the center of mass ( c.o.m. ) of this system toContinue reading “ENERGY AND MOMENTUM: Elastic Collisions and the Center of Mass Velocity ( Part 3 )”
Tag Archives: kinetic energy
ENERGY AND MOMENTUM: Final Velocity of Target and Projection After Elastic Collision ( Part 1 )
Q: Within a given system, a projectile moves with a constant velocity ( v1 ) prior to colliding with a stationary target of equal mass ( m1 = m2 ). Since the system is isolated from outside forces, momentum ( p ) and kinetic energy ( KE ) both are conserved during the collision. (Continue reading “ENERGY AND MOMENTUM: Final Velocity of Target and Projection After Elastic Collision ( Part 1 )”
ENERGY AND MOMENTUM: What is the Initial Velocity of the Marble?
Q: A collision occurs between two marbles of equal mass ( m1 = m2 ). Marble ( m2 ) is initially at rest, and ( m1 ) travels with a velocity ( v1 ). After colliding, ( m2 ) acquires a velocity ( v2′y ) of 1.10 m/s and travels 400 from the original lineContinue reading “ENERGY AND MOMENTUM: What is the Initial Velocity of the Marble?”
ENERGY AND MOMENTUM: Stacked Ball Drop, Impulse, and the Galilean Transformation
Q: Three balls of mass m1, m2, and m3 fall together towards the earth. They accelerate until impact, and once the three-ball system collides elastically with the earth’s surface, the balls within the system approach one another with an instantaneous velocity ( v ). The momentum ( p = mv ) = ( m1 +Continue reading “ENERGY AND MOMENTUM: Stacked Ball Drop, Impulse, and the Galilean Transformation”
ROTATIONAL MOTION: Rotational Inertia
Q: A student sits atop a freely rotating stool holding two dumbbells, each of which has a mass of 3.09 kg. When the student’s arms are extended horizontally outward, the dumbbells are 0.99 m from the axis of rotation. There are 180 degrees of separation between the extended arms. The student rotates with an angularContinue reading “ROTATIONAL MOTION: Rotational Inertia”
ENERGY and MOMENTUM: How Fast Will the Block Move When a Compressed Spring is Released?
Q: A spring with a spring constant k = 100 N/m is compressed a distance ( x ) = 100 mm. A block with a mass ( m ) = 0.250 kg is placed next to the spring. The surface upon which the block rests is frictionless and horizontal. When the spring and block areContinue reading “ENERGY and MOMENTUM: How Fast Will the Block Move When a Compressed Spring is Released?”
FORCE AND ACCELERATION: The Gravitational Force of Attraction
Q: An arbitrary distance separates two objects of equal mass. If the mass of each object is doubled, and the distance between the two objects is tripled, how will the force of attraction between the two objects change? A: This question regards the gravitational force of attraction that exists between two objects with well-defined massesContinue reading “FORCE AND ACCELERATION: The Gravitational Force of Attraction”
ENERGY AND MOMENTUM: Subatomic Collisions, Billiard Balls, and the 90-Degree Rule ( Part 1 )
An elastic collision, within which kinetic energy ( KE ) and momentum ( p ) are conserved, is mathematically modeled in terms of momentum as follows: pi = pf , and m1v1i + m2v2i = m1v1f + m2v2f where p = mv, and m = mass in kilograms ( kg ), and velocity ( vContinue reading “ENERGY AND MOMENTUM: Subatomic Collisions, Billiard Balls, and the 90-Degree Rule ( Part 1 )”
ENERGY AND MOMENTUM: Which Object Will Roll Down a Hill More Rapidly?
If a buggy and a sphere of equal masses begin rolling side-by-side down a hill, which will reach the bottom of the hill first ( neglecting wind resistance ) ? For simplicity, we should pretend that the energy transfer in this problem is 100% efficient: no losses occur due to sound, random vibrations, or windContinue reading “ENERGY AND MOMENTUM: Which Object Will Roll Down a Hill More Rapidly?”
ELASTIC COLLISIONS: Kinetic Energy, Momentum, Two Equations, and Two Unknown Variables
If a + b = c, and if b = e + f, then it’s also true that a + e + f = c. Any time a variable is common to two or more similar equations, solving one of the two equations will enable us to substitute the common variable into the remaining equation.Continue reading “ELASTIC COLLISIONS: Kinetic Energy, Momentum, Two Equations, and Two Unknown Variables”
RENAISSANCE PHYSICS 