Refraction occurs when a wave
a.
enters a new medium at an angle.
b.
hits a surface through which it cannot pass.
c.
moves around a barrier.
d.
interferes with another wave.

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.

beta is electron from nucleus

something from nucleus has changed, but charge must be same for cons of charge

c) power lifting, will be your answer.

,

deku ❤