A force of 10 N acts on an object, causing it to accelerate at 2.5 ms 2. What is the mass of the object?

Your answer is 1.5 hope i  

Special care would be an answer

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.