Vertical circular motion

Get the most by viewing this topic in your current grade. Pick your course now.

Now Playing:Vertical circular motion– Example 1
Examples
  1. Uniform vertical circular motion

    A 0.315 kg ball attached to the end of a 0.700 m string is swung in a vertical circle so that it has a constant speed of 4.50 m/s. What is the tension in the string at the top and bottom of the circular path?

    Horizontal circular motion
    Jump to:Notes
    Notes
    In this lesson, we will learn:
    • Solving problems involving vertical circular motion

    Notes:

    • An object moving in a circular path is in circular motion. If the speed of the object is constant, it is uniform circular motion.
    • An object in uniform circular motion does experience acceleration, even though its speed is constant. Remember, acceleration is change in velocity, and a velocity is made up of speed and direction. For the object to move in a circle, the direction of its velocity must change constantly. This change in direction is the acceleration, called centripetal acceleration ("centripetal" means "towards the center"). For an object moving in a circular path, the centripetal acceleration vector is always pointed towards the center of the circle.
    • Like any other type of acceleration, centripetal acceleration is caused by a force (called centripetal force). The centripetal force vector also always points towards the center of the circle.
    • In order for an object to be moving in a circular path, the net force acting on the object must be a centripetal force (a force that always is pointed towards the center). When multiple forces act on an object in circular motion, those forces must add up to a centripetal force. It is important to understand that centripetal force is not a separate force that acts on an object. It is a net force which follows a specific rule: it always points towards the center of the circular path.
      • In a horizontal circular motion problem, any forces acting on the object in the vertical direction must balance so that ΣFvertical=0N\Sigma F_{vertical} = 0N (otherwise the object would accelerate vertically). Only horizontal forces will contribute to the net force causing circular motion.
    Period and Frequency

    T=totaltime#ofrevolutionsT = \frac{total time}{\# of revolutions}

    f=#ofrevolutionstotaltimef = \frac{\# of revolutions}{total time}

    T=1fT = \frac{1}{f}

    T:T: period, in seconds (s)

    f:f: frequency, in hertz (Hz)


    Centripetal Acceleration

    ac=v2r=4π2rT2a_{c} = \frac{v^{2}}{r} = \frac{4\pi^{2}r}{T^{2}}

    ac:a_{c}: centripetal acceleration, in meters per second squared (m/s2)(m/s^{2})

    v:v: velocity, in meters per second (m/s)

    r:r: radius, in meters (m)

    T:T: period, in seconds (s)