A ball is thrown upward with an initial velocity of 12m/when the ball rises to 19m above its starting point, its velocity is 3m/s reaches its peak and comes back down to 19m above the starting point. What is its velocity now. a.-12m/s
b.12m/s
c.-3m/s
d.3 m/s

The purpose of a lab is to do your "expirements" the importance of the topic is so you can now what the story is about and the last one is because no one is me with my question ( what is 3 over 4 x - 9 = 27 maybe you can )

Sounds propagates through some kind of medium. usually it's air, but it goes just as well through solid objects like walls, windows etc. a soundwave will compress the (air)molecules in front of it, and if this increased density wave hits your ears, you register it as sound. solid objects like walls are a lot denser than air, this means that they will damp a wave, but also carry it easier.

The shape  of the trajectory of a projectile is a parabola or a curve