# I dont understand how to get velocity from (6.00i - 1.00j) ?

• nukeman
In summary, the conversation discusses how to find the velocity from a given vector (6.00i - 1.00j) and suggests using Pythagoras' theorem to find the magnitude of the velocity vector. The conversation also mentions using the dot product to find the magnitude of the vector and suggests looking up how to find the resultant of two vectors at right angles. The conversation also asks if the person has studied vector mechanics.

#### nukeman

I don't understand how to get velocity from (6.00i - 1.00j) ??

## Homework Statement

Hey all, I have a problem where I am asked to find the velocity of something, but some data I am given says: "A 3.00kg object has a velocity (6.00i - 1.00j) m/s "

What is the velocity of that? I don't quite understand how to get vel from that vector.

## The Attempt at a Solution

You are given the two components of the vector v. Phytagoras will tell you how to find the magnitude of the velocity vector.

I was reading over, and it says v^2 = v * v

?

so, is it v = square root 6?

Wot, no notes or textbook?
Whats 6squared + 1squared?

Look up how to find the magnitude and direction of a vector, given it's xy components. Or even how to find the resultant of two vectors at right angles.

I think that you were reading that the dot product (or scalar product) of the two vectors $\underline{v}$ gives the MAGNITUDE of the vector $\underline{v}$.

i.e.$\underline{v}$.$\underline{v}$=v$^{2}$

Have you studied vector mechanics?

## 1. What is velocity?

Velocity is a measure of an object's speed and direction of motion. It is a vector quantity, meaning it has both magnitude (speed) and direction.

## 2. How is velocity different from speed?

While speed only measures how fast an object is moving, velocity also takes into account the direction of motion. For example, a car traveling at 60 miles per hour north has a different velocity than a car traveling at 60 miles per hour south.

## 3. How is velocity calculated?

Velocity is calculated by dividing the displacement (change in position) by the time it took to travel that distance. It can also be calculated by multiplying the speed of an object by the cosine of the angle between its direction of motion and a reference direction.

## 4. What do the numbers in the expression (6.00i - 1.00j) represent?

The numbers represent the components of a vector in Cartesian coordinates. In this case, 6.00 represents the x-component and -1.00 represents the y-component. The "i" and "j" are unit vectors in the x and y directions, respectively.

## 5. How can I use (6.00i - 1.00j) to find the velocity?

Since (6.00i - 1.00j) represents a vector in Cartesian coordinates, you can use it to find the magnitude and direction of velocity. The magnitude of velocity can be found by calculating the length of the vector using the Pythagorean theorem. The direction can be found by calculating the inverse tangent of the y-component divided by the x-component.