Two kids are roller skating. amy with the mass of 55kg, traveling at 3m/s. jenny who has a mass of 40kg is traveling at 5m/s in the opposite direction. they crash into each other and hold onto each other so now they are skating together, how fast are they traveling? t

m1v1+m2v2=(m1+m2)=v
is the equation needed for this, i need with how to do the steps, it's on my review, and you!

An electron moves with a constant horizontal velocity of 3.0 × 106 m/s and no initial vertical velocity as it enters a deflector inside a tv tube. the electron strikes the screen after traveling 26 cm horizontally and 19 cm vertically upward with no horizontal acceleration. what is the constant vertical acceleration provided by the deflector? (the effects of gravity can be ignored.)