Recent content by vertex78

  1. V

    Calculating the Velocity Vector of a Tennis Ball

    Trying to get my head around the velocity vector that a tennis ball goes after it is hit with a tennis racket. To make matter easier, I am only thinking about it in terms as if the ball is sitting in midair motionless when the racket hits it. Say the ball is hit with a force of 1N and the...
  2. V

    What is the moment of rotational inertia about the axis indicated?

    I don't really understand how I have assumed the contribution is zero. I know this must be from my lack of understanding this correctly but I keep thinking that since I am using the full weight of the object and the length of side b then I would taking every particle in account. Can you...
  3. V

    What is the moment of rotational inertia about the axis indicated?

    it seems like the height of the rectangle is irrelevant since each particle at a particular length will have the same rotational inertia regardless of the height. Am I missing something here?
  4. V

    What is the moment of rotational inertia about the axis indicated?

    Homework Statement The rectangle shown has a mass, m. The sides are made of uniform thin wire. The short side is of length a, and the long side is of length b. If m = 5.50 g, a = 0.05 cm and b = 0.1 cm, what is the moment of rotational inertia about the axis indicated? (ignore the x's)...
  5. V

    Particle sliding off turntable - find friction

    I'm not sure how to find all the forces on the particle. Here is what I know The particle will have a tangential velocity The particle will have a centripetal acceleration that is perpendicular to the tangential velocity Then the particle will have gravity and a normal force. I just can't...
  6. V

    Calculating Tangential Acceleration of a Particle on a Flywheel

    Ok my bad on the angular acceleration equation I wrote, I am not sure what I was thinking, I had it written down on paper correctly, somehow I added in a 2PI into the equation I was using. For another question for the same problem I had to find the angular accleration in rev/min^2. So that also...
  7. V

    Particle sliding off turntable - find friction

    ok so centripetal force is a_c = \frac{v^2}{r} and v equals the tangential speed which is 1.14 m/s, and r = .14m. So centripetal force would equal 9.345 m/s^2 right? Or is that the centripetal acceleration? It seems those two terms are used interchangeably. So what is the difference between...
  8. V

    Particle sliding off turntable - find friction

    Homework Statement A turntable rotates at 78 rev/min A particle on the turntable is located 0.14 m from the center of the rotating turntable The particle on the turntable has a mass of 16 g. Calculate the force of friction which keeps it from sliding off Homework Equations f_s =...
  9. V

    Calculating Tangential Acceleration of a Particle on a Flywheel

    Homework Statement The flywheel of a steam engine runs with a constant angular speed of 137 rev/min. When steam is shut off, the friction of the bearings and the air brings the wheel to rest in 2.7 h. What is the magnitude of the tangential component of the linear acceleration of a...
  10. V

    Angular acceleration of a pulsar

    A pulsar is a rapidly rotating neutron star that emits radio pulses with precise synchronization, there being one such pulse for each rotation of the star. The period T of rotation is found by measuring the time between pulses. At present, the pulsar in the central region of the Crab nebula has...
  11. V

    What is the Final Velocity of the Astronaut After Throwing Away the Power Pack?

    i tried what you said dr pizza and I could not get the correct answer. So i tried without switching the frame of reference and did this: v1i = initial velocity of astronaut v1f = what i am looking for v2i = initial velocity of the power pack v2f = final velocity of the power pack using...
  12. V

    What is the Final Velocity of the Astronaut After Throwing Away the Power Pack?

    Homework Statement An astronaut runs out of fuel in his power pack while drifting at 1.0 m/s away from the Space Shuttle. The astronaut removes his 25.0 kg power pack and throws it away at 2.9 m/s relative to the shuttle and in the direction away from the shuttle. The mass of the astronaut...
Back
Top