Ugggh physics about velocity?

A 90 kg halfback running north with a speed of 10 m/s is tackled by a 120 kg opponent running south at 4 m/s. Compute the velocity of the two players just after the tackle.

2 Answers

  • Assume that at tackle time they Stick TOGETHER (don’t bounce apart) then northern

    (call it negative -) momentum is

    90 x 10= -900 kg.m/sec and momentum south is 120 x 4 = +480 kg.m/sec.

    now momentum is additive and conserved so the combined mass of the two players is

    (-900 +480)kg. m/sec =-420 kg the combined bodies will move in negative direction (which is NORTH at 420/210 =2m/second.

    Source(s): went to school
  • conservation of momentum – m1u1+m2u2= v x (m1+m2)

    (90×10) +(120x-4)=v(210)


Leave a Comment