Acceleration is defined as a change in velocity. In other words, it is a change in speed or a change in direction. It is how much time it takes something to go from one velocity to another. Remember that velocity is speed and direction. If you go straight ahead on your bike at a constant speed of 5 mph, you are not accelerating because neither your speed nor your direction is changing. Now, if you are stopped at a stop light and it turns green, you are accelerating as your speed increases from zero to 10 mph.
The word ‘acceleration’ is a little confusing, since sometimes people say someone is ‘accelerating’ when they really mean that they are ‘moving really fast’. Acceleration simply means changing speed or direction, not if they are going fast or not. Also, in physics we don’t use the word deceleration. We use positive and negative acceleration. So if you went from 10 mph to zero, you’d say that you have a negative acceleration, not deceleration.
Now what happens if you are in a car and it turns a corner at a constant speed of 15 mph? Is it accelerating or not? Well, the speed is not changing but its direction is, so it is indeed accelerating.Remember back when we talked about gravity? We learned that gravity accelerates things at 32 feet per second². Now this may make a little more sense. Gravity made something continue to increase in speed so that after one second of having the force of gravity pull on something, that something has reached a speed of 32 feet per second. When that thing started falling it was at 0 velocity, after a second it’s at 32 feet per second after 2 seconds it’s at 64 feet per second and so on.It’s the old formula v = gt or velocity equals the gravitational constant (32 ft/s²) times time.
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If the object is slowing down, the acceleration is in the opposite direction from velocity. If an object is speeding up, then both are in the same direction.
In other words, the acceleration’s polarity is based on the change in the absolute value of the velocity? i.e. if the absolute value of the velocity decreases in magnitude on the chart, it is a negative acceleration?
It’s meant as an option lab the kids can do. We left the header in there so you could go to the right unit and module if you need to go back to review the background information for this lab (Unit 2, etc).
About 700 of the 1500 science experiments in this section have worksheets, but what we’re really after here is for kids to learn how to create their own. The worksheet themselves is more like training wheels, to model what we’re looking for when doing the science experiment. Eventually, kids will be making their own data tables and asking their own questions, designing their own experiments and figuring out their own conclusions – that’s the real result we’re after. There’s a detailed video on how to create your own here: https://www.sciencelearningspace2.com/science-with-aurora/
And I guess I was also wondering if there are daily worksheets? Am I missing that or do some videos not have worksheets?
When I printed off the lessons, the Driveway Acceleration worksheet printed right after the Acceleration Lesson. It says that it is Unit 2, Lesson 2, but are they supposed to do this worksheet at this time or save it until later?
yes the negative number needs to mean something. On a scalar, it doesn’t mean anything, but on a vector it will indicate direction.
So, can only vector equations have negative numbers?
Yes the solutions are written out on the last pages of the HW set. Do you see them there?
We are doing the problems in the homework. We can’t figure out how to get the right answers for the acceleration problems. For example, we got 25 and it is supposed to be 20. Can we see this work somewhere? Are there written out solutions for each homework problem?
I have no idea how to figure this out as I am not a science person. Thank you:)
Yes, it’s normal to not get a perfectly straight line. In fact, what scientists normally do is a “best fit line” which means they take a ruler and line it up so that the same number of data points fall on each side of the ruler, and then draw the line that way. There’s a lot of room for error when doing science experiments – it’s a whole art in itself to taking good data. We’re going for effort at this point more than perfect results.
Can you send me an image of your work? [email protected]
Hello. So…. My son just finished reading and watching the video on acceleration. He started the graphs on the worksheets Unit 2: Lesson 2 and is not getting a straight line. Are we going to ahead? Did we start the worksheets too early? How do we know when to do the worksheets?
It’s just the magnitude (the amount of the acceleration) without the direction information included.
For velocity (because it’s easier to visualize): instead of 10 feet per second heading west for example, it would be just 10 feet per second.
How can something be accelerating as a scalar without a direction?
It looks like seconds x seconds in the denominator. Acceleration is velocity per unit time, which is feet per second per second, or feet per seconds squared (ft/s2).
I am working with 8th graders who are wondering how the 32 ft/second squared works math-wise. If you are squaring the seconds, what does that look like mathematically. The quote above is ” When that thing started falling it was at 0 velocity, after a second it’s at 32 feet per second after 2 seconds it’s at 64 feet per second and so on.It’s the old formula v = gt or velocity equals the gravitational constant (32 ft/s²) times time.” So, what does that look like plugged into the formulas.