Help! The answers I put are just what I think it is, but I'm not sure and I'm confused. Please help!

The pictures are attached.

When someone slams her books on a table the kinect energy is transferred into vibrations that travel to your ears as sound waves which statement describes the movement of those waves

What is the length x of the side of the triangle below? (hint: use the cosine function)

After a big snowfall, you take your favorite rocket-powered sled out to a wide field. the field is 195 m across, and you know that your sled accelerates at a rate of 3.65 m/s2 when the rocket is on. how much time will it take the sled to cross the field starting from rest, assuming the rocket is on the whole time?