Recent content by kmb11132

  1. K

    Average Angular Acceleration of a CD

    You're exactly right. I'm using the WileyPlus system and it expected scientific notation without explicitly stating so.
  2. K

    Average Angular Acceleration of a CD

    Homework Statement A CD has a playing time of 59.8 minutes. When the music starts, the CD is rotating at an angular speed of 460 revolutions per minute (rpm). At the end of the music, the CD is rotating at 202 rpm. Find the magnitude of the average angular acceleration of the CD. Express...
  3. K

    Work done by a force changing the distance of a satellite's orbit

    I incorrectly found the work to be the difference between the initial and final kinetic energies above.
  4. K

    Work done by a force changing the distance of a satellite's orbit

    Homework Statement A 5530-kg satellite is in a circular Earth orbit that has a radius of 1.81 × 10^7 m. A net external force must act on the satellite to make it change to a circular orbit that has a radius of 8.01 × 10^6 m. What work must the net external force do? Homework Equations...
  5. K

    Finding initial velocity of a free-falling object that launched off a cliff

    Thank you so much! I didn't think there was enough information to do that but, well, there definitely was. For the sake of future Googlers coming to this page what I did was... Take this equation: d = v_i*t + .5*a*t^2 and solved for the y displacement: d_y = 0 * .77 + .5 * -9.8 *...
  6. K

    Finding initial velocity of a free-falling object that launched off a cliff

    That's what I thought, but I figured in the absence of all other ideas I'd give a 45-45-90 triangle a shot. I tried all of the kinematic equations for projectile motion in every way that I thought made sense and they all incorrectly lead me to a v_ix of 13.38m/s. I know that I'm using the...
  7. K

    Finding initial velocity of a free-falling object that launched off a cliff

    Assuming the car fell at a 45 degree angle the magnitude of its x displacement would be 5.23 meters in .77 seconds. Without an x acceleration/assuming constant speed this would work out to a v_ix of 6.79m/s. This is also incorrect. There is still some key to solving this problem that's...
  8. K

    Finding initial velocity of a free-falling object that launched off a cliff

    So what I found would be v_av not v_f correct? I'm kind of stuck right now because I don't think I can use equations that incorporate v_f, and those that incorporate v_i, a, d, and t all produce 13.38 as the initial velocity. I don't think I can separate this problem into vertical and...
  9. K

    Finding initial velocity of a free-falling object that launched off a cliff

    Homework Statement A child operating a radio-controlled model car on a dock accidentally steers it off the edge. The car's displacement 0.77 s after leaving the dock has a magnitude of 7.4 m. What is the car's speed at the instant it drives off the edge of the dock? @t = .77s displacement is...
  10. K

    Finding average acceleration by combining constant velocity vectors

    Thanks Peter, that makes a lot of sense. So after trying to remeasure and calculate everything accurately here is what I came up with: Segment #1: +25km in 1hr (given data) v_i = 0km/hr v_av = 25km/hr v_f = 50km/hr a_av = 50km/hr^2 Segment #2: +7.25km in 1.2hr (given data) v_i =...
  11. K

    Finding average acceleration by combining constant velocity vectors

    Yes, I attempted to calculate the velocities and average speed. If average acceleration is: (v1-v0)/(t1-t0) then I thought that would be (25km-0km)/(1hr-0hr) in kilometers per hour^2 if it started from rest and traveled 25km in 1 hour. Okay so I see that I'm doing something wrong with the...
  12. K

    Finding average acceleration by combining constant velocity vectors

    Homework Statement The given data is a graph depicting the distance (km) that a bus travels over 3.5 hours. The trip is broken up into three linear segments. I am supposed to find the average acceleration over the entire trip in km/hr^2. I am told that the answer will be negative. Edit...
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