Vector & scalar

There is a difference between vector and scalar ..

A scalar quantity is a one dimensional measurement of a quantity, like temperature, or weight.  A vector has more than one number with it.   A simple example is velocity.   You can have more that two numbers associated with a vector.  For example you can add a height dimension to velocity and say, for example, ' I am going uphill at a 5 degree slope in the Northeast direction'.    Vectors are frequently broken down into their components along an orthogonal coordinate system, like the x and y axes.   So you can say the y-component of my speed is 3 km/sec and the x-component of my speed is 4 km/sec.   The magnitude, or speed is the square root of the sum of the individual components, 5 in this case.  The direction with respect to the x-axis would be given by the arctangent of V_y / Vx or 36.9 degrees.

Four forces

In class we learned about forces .. The four types we learned applied force, gravitational force , normal force , tenision force.

We use these forces all the time in out everyday lives 

1. Applied force, when you have a race car you need to pull it back and the force you put when you pulled it back is the force you put in the car.

2.Gravitational force, It's like the Earth pulling on you and keeping you on the ground. That pull is gravity at work.

3.Normal force, when a glass cup is on the table, what  prevents objects from falling into whatever it is they are sitting on.

4.Tension force, when you have two batteries both ends attracts, the (-) & (-) dont attract but the force going agianst it not to touch is the tension.

Acceleration

A sports car & bus are stopped at a traffic light , the two motions of these cars goes to a 30mph.

 There is a difference between the sports car & the bus.. The car is lighter, it's basically half of the weight of the bus bus.. But the bus has a disasvantadge because its heavier & it has to maintain its 30 mph , it has to be double acceleration...double the pressure of the accreraltor

 The similarity of the car & bus is that the velocity is the same both are going at the same pace, also same distance

GUESS method

Today in class we learned somehing called GUESS method. We learned this in class so we would be able to find out the velocity or time change. Each letter stands for a step

The acronymn is (G.U.E.S.S)

G: To say any information in the problem

U: It's the unkown part,no one know what it is,it's pretty much the variable your trying to find

E: Its the equation ,to sum up the equation(formula your going to use)

S: Subsitution!! Its for replacing all the correct empty variables

S:Solve the rest by writing the equation out in its full form (dont forget to put in the variable,units, etc.) 

Distance vs. Time Graphs

Today in class we had a motion detector & we had a board so what the board was  a target for the motion detector.. We had had to walk forward & backword so it would know the time & position.When we stayed at the sam position the motion line would stay in a straight line, we moved back the position line would go higher , we moved in towards the motion detector the position line would go lower,so it depended on your movements you would get different results.

Why do i think these are necssecary is because when we measure motion we measure its speed interval & to see how many movements it would take to be at that certain amout of seconds. That is why i think these grapghs would be important to our science class