ENERGY AND MOMENTUM: Elastic Collisions and the Center of Mass Velocity ( Part 3 )

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 )”

ENERGY AND MOMENTUM: Elastic Collisions and the Center of Mass Velocity ( Part 2 )

In Part 1 of this entry, it was determined that the center of mass between objects moving with constant velocities is also constant ( vcm ): We will now use mass ( kg ) and instantaneous-distance coordinates along ( x ) to determine the system’s center of mass. Let’s begin using the x-coordinates of (Continue reading “ENERGY AND MOMENTUM: Elastic Collisions and the Center of Mass Velocity ( Part 2 )”

ENERGY AND MOMENTUM: Elastic Collisions and the Center of Mass Velocity ( Part 1 ) 

A system’s center of mass is the location where the average mass distribution of the system is located. Consider a system in which two equal masses rest at the ends of a balance: The sum of torques acting upon the system is zero, and it will remain in static equilibrium until acted upon by anContinue reading “ENERGY AND MOMENTUM: Elastic Collisions and the Center of Mass Velocity ( Part 1 ) “

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 )”

FORCE AND ACCELERATION: Net Force Exerted on a Ring

Q: How may we determine the net force ( F ) exerted on the ring below? A: We must first reduce the F1 and F2 vectors into their x/y-components: The F1y and F2y components of F1 and F2 oppose the motion of F3. The net force in the y-direction is as follows: Fnety = F2yContinue reading “FORCE AND ACCELERATION: Net Force Exerted on a Ring”

ELECTRONICS: Kirchhoff’s Laws

Q: What are the values of the currents ( I ) and unknown voltage drops ( V ) across the resistors ( R ) pictured below? A: The first problem-solving step involves assigning labels to the junctions ( j ) in the circuit: We must now sketch the currents flowing in the circuit: The currentContinue reading “ELECTRONICS: Kirchhoff’s Laws”

FORCE AND ACCELERATION: 3-4-5 Right-Triangle Mathematics

Q: Two men attempt to pull a box in the diagram below: What is the resultant force in Newtons ( N ) exerted on the box? A: This is a classic question involving a 3-4-5 right triangle. Trigonometry and the Pythagorean Theorem enable us to solve the problem using the numbers 3, 4, and 5.Continue reading “FORCE AND ACCELERATION: 3-4-5 Right-Triangle Mathematics”

ELECTROSTATICS: Electric Field at the Center of an Equilateral Triangle

Q: Three point charges located at the corners of an imaginary equilateral triangle carry charges of +8 µC, +3 µC, and -5 µC, respectively. A distance of 0.5 m separates the charges from one another. What net electric field ( E-field ) will a positive test charge experience when placed at the triangle’s center? A:Continue reading “ELECTROSTATICS: Electric Field at the Center of an Equilateral Triangle”

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: A Windy Day at the Lake

Q: Wind blows a 43.0 kg raft across a lake at 1.1 m/s northward relative to the water underneath. It carries a passenger whose mass is 38.0 kg. The passenger begins to walk westward at 0.71 m/s. What is the final velocity of the raft relative to the water? A: We first determine the momentumContinue reading “ENERGY AND MOMENTUM: A Windy Day at the Lake”