Question

A 120 kg lineman moving west at 2 m/s tackles an 80 kg football fullback moving east at 8 m/s. After the collision both players move east at 2 m/s.

Answer 1

Answer:

m1u1+m2u2=(m1+m2)V

400kgm/s=400kgm/s

Explanation:

A 120 kg lineman moving west at 2 m/s tackles an 80 kg football fullback moving east at 8 m/s. After the collision both players move east at 2 m/s.

the principle of linear ,momentum states that the total momentum before collision must be equal to the total momentum after collision.

m1u1+m2u2= before collision

m1=mass of the line man

u1=speed of the lineman

m2=mass of te full back

u2=speed of te full back

V=common velocity after the collision

we designate the east direction as negative

and designate the east direction as positive

-120*2+80*8

400kgm/s

momentum after collision

(m1+m2)V

120+80)2

400kgm/s

therefore 400kgm=400kgm/s

this satisfy the principle of linear momentum

Answer 2

The answer is Vf = -2 m/s