Physics

A girl standing on a stationary uniform plank 10m long. The plank can move with negligible friction along the surface of the water.

A) the girl walks along the plank with a velocity of 2ms-1 relative to the plank until she reaches the end of the plank. The centre of mass of the system is now 2m from the end of the plank. Calculate the mass of the girl is the mass of the plank is 12.6kg.

  1. 👍 0
  2. 👎 0
  3. 👁 176
asked by Peter
  1. The center of mass of the system continues at rest because there are no external forces on the system.

    cg at 0 forever
    m girl * distance from 0 = m plank * distance from 0
    center of plank moves 3 to right if girl now 2 meters from CG of system to left
    3*12.6 = 2 m
    m = 3 * 6.3 = 18.9 kg

    1. 👍 0
    2. 👎 0
    posted by Damon

Respond to this Question

First Name

Your Response

Similar Questions

  1. physics

    A uniform plank AB is 10m long and has mass of 14km. The plank rest on two support at A and B. A lead of mass 8kg is placed on the plank at a point c 4meter away from A. Calculate the reactions at the support at A and B on the

    asked by dawodu ibukun on November 1, 2015
  2. physics

    A 48.2 kg girl is standing on a 160. kg plank. The plank, originally at rest, is free to slide on a frozen lake, which is a flat, frictionless surface. The girl begins to walk along the plank at a constant velocity of 2.00 m/s to

    asked by Anonymous on October 21, 2012
  3. physics

    A 48.2 kg girl is standing on a 129 kg plank. The plank, originally at rest, is free to slide on a frozen lake, which is a flat, frictionless surface. The girl begins to walk along the plank at a constant velocity of 1.66 m/s

    asked by sidney on October 12, 2011
  4. physics

    A 48.2 kg girl is standing on a 160. kg plank. The plank, originally at rest, is free to slide on a frozen lake, which is a flat, frictionless surface. The girl begins to walk along the plank at a constant velocity of 2.00 m/s to

    asked by Anonymous on October 22, 2012
  5. PHYSICS 1 ..'''''''''''''''''''''''' helllpppppppp

    A girl of mass (Mg) is standing on a plank of mass (Mp). Both are originally at rest on a frozen lake that constitutes a frictionless, flat surface. The girl begins to walk along the plank at a constant velocity (vgp) to the right

    asked by Rrjey on February 26, 2013
  6. Physics

    Two men are carrying a girl on a large plank that is 10m long and weights 200N. If the girl on a plank weighs 445N and sits 3m from one end, how much weight must each man support?

    asked by Clangclang on September 14, 2014
  7. Physics

    Question Part Points Submissions Used A 45.0-kg girl is standing on a 160-kg plank. The plank, originally at rest, is free to slide on a frozen lake, which is a flat, frictionless surface. The girl begins to walk along the plank

    asked by Allie on October 4, 2011
  8. Physics URGENT!!!

    A 41.8 kg girl is standing on a 142. kg plank. The plank, originally at rest, is free to slide on a frozen lake, which is a flat, frictionless surface. The girl begins to walk along the plank at a constant velocity of 1.40 m/s to

    asked by Anonymous on October 15, 2012
  9. physics

    A 45.0 kg girl is standing on a 163 kg plank. The plank, originally at rest, is free to slide on a frozen lake, which is a flat, frictionless surface. The girl begins to walk along the plank at a constant velocity of 1.45 m/s

    asked by Elisa on July 7, 2008
  10. physics

    A 43.3 kg girl is standing on a 125 kg plank. The plank, originally at rest, is free to slide on a frozen lake, which is a flat, frictionless sup- porting surface. The girl begins to walk along the plank at a constant speed of

    asked by John on November 12, 2012

More Similar Questions