Recent content by RedDanger

  1. R

    The relation between atoms' kinetic energy and the energy levels

    I'm assuming that by "hot gas" you're referring to a plasma, in which case I'm fairly certain that a large amount of thermal energy is supplied. For example, consider an ICP laser that reaches temperatures of up to 10000K. I can't think of another type of hot gas which would emit in the Vis...
  2. R

    The relation between atoms' kinetic energy and the energy levels

    A collision can only result in a vibrational or rotational energy level transition. This is a transfer of kinetic energy. I would speculate (so don't quote me on this) that it would require extremely large amounts of thermal energy to cause an electronic transition as a result of kinetic energy...
  3. R

    Harmonic Oscillator and Total Energy

    Okay, so if a harmonic oscillator has a restoring force given by Hooke's Law such that Fs = -kx and its integral gives the potential energy associated with the restoring force: PE = -(1/2)kx2 Then for the total energy of a harmonic oscillator, why is the TE: TE = Evibration +...
  4. R

    Finding force without acceleration

    Okay, so for the first part I solved for F and got 229N. For the second part, the amount of force exerted on the door should be the same because neither the mass of the bullets nor their final velocity changes due to the type of collision. Is this correct?
  5. R

    What Is the Angular Acceleration and Distance Traveled by the Paint Splotch?

    Homework Statement A flywheel rotates at a rate of 20 rpm. A motor provides a constant angular acceleration so that 30 s later it turns at a rate of 70 rpm. There’s a tiny splotch of paint on the flywheel, located 0.10 m from its center. During the acceleration period, what is the angular...
  6. R

    Finding force without acceleration

    Homework Statement A machine gun fires 22 g bullets horizontally at 260 m/s at a constant rate of 40 bullets/s. (a) If the bullets embed themselves in a thick wooden door, what is the average force exerted on the door? (b) If the bullets hit a steel door and rebound elastically, what is the...
  7. R

    What are the speed and direction of each ball after the collision?

    Homework Statement A 0.060kg tennis ball, moving with a speed of 2.50m/s, collides head-on with a 0.090kg ball initially moving away from it at a speed of 1.15m/s. Assuming a perfectly elastic collision, what are the speed and direction of each ball after the collision? Homework Equations...
  8. R

    Work-energy theorem and resistive forces

    Homework Statement A skier slides down a hill, starting from rest at a height of 250m above the bottom of the hill. She skis over an intermediate hill, whose height is 100m above the bottom of the hill. If resistive forces are neglected, what is the speed of the skier a) at the top of the...
  9. R

    Work-energy theorem and Tension Force

    Homework Statement While running at a speed of 5.0m/s Tarzan grabs a 9.0m long vine hanging vertically from a tall tree in the jungle and swings on it. As he swings on the vine, how much work is done on him by the tension force in the vine? To what maximum vertical height can he swing if he...
  10. R

    Compare the tension in the rope

    This really cleared it up for me! Thanks!
  11. R

    Compare the tension in the rope

    Homework Statement The ends of a rope are tied to (a) two horses, (b) a tree and a horse, and (c) a tree and two horses, as shown. Each horse pulls with the same magnitude force. Compare the tension in the rope for the three situations. Explain your reasoning.Homework Equations F = ma The...
Back
Top