In Unit 3 we learned about accelerations, graphing acceleration and about what Galileo theorized. We had a lot of exciting experiments in Unit 3. In Unit 3 all laws are the same as Unit 2.

Laws:
1) The slope of a position vs time graph is velocity.
2) The slops of a velocity vs time graph is acceleration.
3) The area under the 'cure' of the line on a graph is distance travelled.


For example today we were asked a question. If two balls (a tennis ball and a kickball) are dropped from the same height at the same time which will hit the ground first? I predicted that the lighter ball or the tennis ball would hit the ground first. I mean seeing that it's so much smaller and lighter surely it should drop first, right? Wrong! Both balls fell to the floor at the same time which really surprised me! It turns out that no matter what the object if they are dropped at the same time from the same height they will hit the ground at the same time! The reason is that the gravity of earth accelerates things at a rate of 10m/s^2. That means that each object accelerates at the same rate which causes them to both hit the ground at the same time. For Galileo to think about things like this such a long time ago he must've been a genius! Who also must've had lots of time if he could just sit around dropping objects.

(This is Mr Blake about to drop the two balls)

We also learned about different equations to figure out missing parts of information. These equations really help during word problems when they ask you to find the rate of acceleration but you're only given the time, distance and initial velocity.

Equations:
D= 1/2at^2 + v0t       We call this d,a,t
V= v0 + at                 We call this v,a,t
V^2= v0^2 + 2ad      And finally this is v,a,d

Acceleration= Change of velocity/time = m/s / s  = m/s^2

v0 or sometimes in other books vi is the original velocity
the normal v stands for ending velocity

All laws that applied to Unit 2 also apply to Unit 3.