Acceleration

Hello!

Today, I am going to talk about acceleration. The one I did previously is motion, which is quite similar with this today's topic.
What is acceleration? Acceleration is the change in velocity divided by the time it takes for the change to occur. This is the definition.

There are three ways of acceleration. It is speeding up, speeding down and changing direction.
Let's start talking about those.
Speeding up means speeding up. It is the other word for accelerating. Accelerating happens only when the motion and the velocity are in same direction. If the ball rolls to the right side and tend to go right side, acceleration will happen. Example of down hill is one of the same direction. You roll the ball down hill and it will accelerate as it goes down. This is also called positive acceleration.
Next, it is slowing down, also deceleration. Opposing speeding up, it happens when motion and velocity is going on the opposite direction. Up hill is another example. When you roll up the hill, the motion is forward. but because of the gravity, it tends to go backward. So motion and velocity is opposite way. This is also called negative acceleration.
 There is a way to calculate acceleration. It is
(Final Speed-Initial Speed) / time. To think easier, I will give you an example. Lets say that you went down the slide. The starting speed (initial speed) will be 0m per seconds .10 seconds later, the speed was 20m per seconds. So now you just need to put the numbers in.
(20m per second-0m per second) /10second. This leaves 2m per s^2.
Acceleration has s^2 always.
Next, there is a graph of acceleration. The bottom line is time, and on the side is meter. When graph rises, it means it has acceleration. But when the slope is downward, it means it is slowing down. When the graph is constant, with no slope, means the speed is constant, nor slowing down or slowing up. There is one method my science tought us about the graph. When the graph has a smily face, it means it is positive graph, and when it is having opposite smiling graph form, it means negative acceleration. This really makes it easy to memorize.

negative graph over here, red line is the negative graph that shows it slows down from 8th seconds.