Physics

Two 0.75m -long pendulums hang side by side. The masses of the pendulum bobs are 65g and 85g . The lighter bob is pulled aside until its string is horizontal and is then released from rest. It swings down and collides elastically with the other bob at the bottom of its arc.To what height does the lighter bob rebound?

  1. 👍 0
  2. 👎 0
  3. 👁 167
asked by Kayla
  1. momentum is conserved, energy is conserved in an elastic collision.

    first pendulum:
    m g h= at the bottom 1/2 m v^2

    v= sqrt (2g*.75) that is velocity of m1 at the bottom. solve for v

    Now, the collision
    momentum:
    .065*v=.065v'+.085v2
    energy:
    1/2 .065v'^2=1/2 .065v'^2+ 1/2 .085 v2^2

    so in those , you have two unknowns v' and v2
    two equations, two unknowns. Solve for v' in the first equation, put it in the second equation, and solve for v2. Have a blank pad with lots of room to do the agebra.
    Now, knowing v2, the height it goes:
    1/2 .085 v2^2= .085 h * g
    solve for h.

Respond to this Question

First Name

Your Response

Similar Questions

  1. Physis Home work

    Two 0.85Mtrs -long pendulums hang side by side. The masses of the pendulum bobs are 50g and 70g . The lighter bob is pulled aside until its string is horizontal and is then released from rest. It swings down and collides

    asked by Don on November 1, 2011
  2. Physis Home work

    Two 0.85Mtrs -long pendulums hang side by side. The masses of the pendulum bobs are 50g and 70g . The lighter bob is pulled aside until its string is horizontal and is then released from rest. It swings down and collides

    asked by Don on November 1, 2011
  3. Physics

    Two pendulums are set up side by side. One pendulum P, consists of a 0.240 kg mass that is suspended on a string that is 65.0 cm long. The other pendulum, Q, has a 0.360 kg mass that is suspended on a string that is 39.0 cm long.

    asked by Steve on January 31, 2013
  4. physics

    A simple pendulum is made by attaching a small cup of sand with a hole in the bottom of a 1.2 m long string. The pendulum is mounted on the back of a small motorized car. As the car drives forward, the pendulum swings from side to

    asked by Bill on September 24, 2010
  5. Math

    The pendulum of a grandfather clock is 90cm long, when the pendulum swings from one side to the other it travels a horizontal distance of 9.2cm, determine the angle in which the pendulum swings.

    asked by Ricki on January 26, 2014
  6. math

    The length of time that it takes for a pendulum to make one complete swing depends on the length of the pendulum. The time in seconds, T, is related to the length in meters, L, through the equation: T=2π√((L)/(9.8)) [it is all

    asked by Jonathan on March 13, 2013
  7. 9th grade math

    the triange is 31cm, side 1 and side 2 have equal lenghts, while side 3 is one centimeter shorter than twice then length of side 1, how long is each side?

    asked by Greg on February 18, 2011
  8. 8th grade math

    the first side of a triangle measures 3 cm longer then the second side the third side is 4cm shorter then twice the second side the perimeter is 31cm. how long is each side?

    asked by Evan on March 7, 2011
  9. Algebra ii

    A 1.25 m long pendulum swings 5.75 degrees on each side of the vertical. Find the length of arc traveled by the end of the pendulum.

    asked by Arielle on November 3, 2011
  10. algebra 1

    The perimeter of a triangle is 72 cenimeters.the second side is twice as long as the first side.the third side is four centimeters shorter than the second side.how long is the first side?

    asked by tyyyyyy on May 27, 2011

More Similar Questions