Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and the Yahoo Answers website is now in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.

Anonymous asked in Science & MathematicsPhysics · 2 months ago

Does anyone know how to do this physics?

Initially, a ball has an angular velocity of 5.0 rad/s counterclockwise. Sometime later, after rotating through a total angle of 5.5 radians, the ball has an angular velocity of 1.5 rad/s clockwise.

a. What is the angular acceleration?

b. What is the average angular velocity?

c. How much time did this take?

Thanks, will award best answer!

2 Answers

  • 2 months ago
    Favorite Answer

    b.  If the angular acceleration was constant, the average angular velocity was 1.75 rad/s CCW.

    a.  2*alpha*theta = (omega-f)^2 - (omega-0)^2 =>

    alpha = [(1.5 rad/s)^2 - (5.0 rad/s)^2]/(2*5.5 rad) = -2.07 rad/s^2.

    c.  The time is (-6.5 rad/s)/(-2.07 rad/s^2) = around 3 seconds but use a calculator.

  • 2 months ago

    The question is ambiguous.  Does the "total angle" include the sum of counter clockwise + clockwise turns.  Or does it mean the net result is 5.5 radians counterclockwise. az_lender has assumed a NET angle.

    The two interpretations are so different as to need a different approach.

Still have questions? Get your answers by asking now.