# Homework Help: Explain what vectors are

1. Jan 31, 2004

### Maxwell

Alright, in my physics class we have been going over vectors. We have done vector addition and subtraction.

Problem is... I do not understand it!! My professor did not explain them well at all, and my teaching assistant did it even worse!!!

Would anyone be so kind as to explain what vectors are, and how I use them? (In a language a first year physics student would be able to understand!)

2. Jan 31, 2004

### gnome

Last edited by a moderator: May 1, 2017
3. Feb 2, 2004

### Maxwell

Anything for Projectiles?

This class is so random. The teacher is a nice guy, but he types his lectures in word and scrolls through them really fast, using examples from the textbook and not really explaining anything.

4. Feb 3, 2004

### himanshu121

Projectiles are usually objects thrown under the gravity

Projectiles are just two dimensions kinematics Problem. U can write kinematics equation in x & y direction The equations will be independent in regard with the two xy directions.

Write the vector equations in two direction

For eg initial velocity v0 at an angle $$\theta_0$$

so u have

$$\vec v=v_0\cos\theta_0 i + (v_0\sin\theta-gt)j$$

similarly u can write for displacement