Answer:
1. sturdy shelter
2. i am preaty shure all of them
Explanation:
Answer:
A. Normal force is always perpendicular to the area of contact between an object and support.
Explanation:
Normal force is defined as the contact force. If there is no contact between the surfaces, they cannot applies a force which is normal on each other. For e.g, the surfaces of a cubical box and the cart cannot applies a force of normal on each other because of no contact.
If, when there is a contact between two surfaces they applies a normal force on each other, and this force is perpendicular to the each other . This normal force is necessary to prevent object to penetrating into other.
An hypothesis is a sort of "untested idea" as to what might be happening. I guess it becomes a theory if experiments back it up, and if the combination leads to other things.So, I'd go for The top pair of answers.
Sound waves travel through all three states of matter: solids, liquids, and gases.