You and your friends are doing physics experiments on a frozen pond that serves as a frictionless, horizontal surface. sofia, with mass 70.0 kg , is given a push and slides eastward. elena, with mass 60.0 kg , is sent sliding northward. they collide, and after the collision sofia is moving at 38.0 ∘ north of east with a speed of 5.20 m/s and elena is moving at 18.0 ∘ south of east with a speed of 9.00 m/s .
what was the speed of each person before the collision?
a. elena's speed:
b. sofia's speed:
c. by how much did the total kinetic energy of the two people decrease during the collision?

Part a)

So speed of Sofia is 11.4 m/s towards East

Part b)

Speed of Elena is 0.95 m/s

Part c)

Explanation:

As we know that both are moving without friction so here total momentum is conserved before and after collision

Part a)

so we have momentum conservation along x direction given as

So speed of Sofia is 11.4 m/s towards East

Part b)

Similarly momentum conservation in Y direction

Speed of Elena is 0.95 m/s

Part c)

Decrease in kinetic energy of two is given as

coil wire, increase current, put iron inside the coil

the chart show the masses and velocities of two colliding objects that stick together after a collision.

according to the law of conservation of momentum, the momentum of the object after the collision is  

answer

1,500

kg • m/s.