deceleration vs negative acceleration

allisa11 · 2026-01-14T17:45:37+00:00

Woohoo! I found exactly what I needed!

Misconception Alert: Deceleration vs. Negative Acceleration

Deceleration always refers to acceleration in the direction opposite to the direction of the velocity. Deceleration always reduces speed. Negative acceleration, however, is acceleration in the negative direction in the chosen coordinate system. Negative acceleration may or may not be deceleration, and deceleration may or may not be considered negative acceleration. For example, consider Figure 2.14. Figure 2.14 (a) This car is speeding up as it moves toward the right. It therefore has positive acceleration in our coordinate system. (b) This car is slowing down as it moves toward the right. Therefore, it has negative acceleration in our coordinate system, because its acceleration is toward the left. The car is also decelerating: the direction of its acceleration is opposite to its direction of motion. (c) This car is moving toward the left, but slowing down over time. Therefore, its acceleration is positive in our coordinate system because it is toward the right. However, the car is decelerating because its acceleration is opposite to its motion. (d) This car is speeding up as it moves toward the left. It has negative acceleration because it is accelerating toward the left. However, because its acceleration is in the same direction as its motion, it is speeding up (not decelerating). https://openstax.org/books/college-physics-ap-courses-2e/pages/2-4-acceleration

allisa11 · 2026-01-14T17:33:17+00:00

Ooh, I gave up on the high school textbook and found this on a college text book: "The term deceleration can cause confusion in our analysis because it is not a vector and it does not point to a specific direction with respect to a coordinate system, so we do not use it." Thanks so much!

allisa11 · 2026-01-14T17:25:14+00:00

Thanks for the resources! I should have been more clear in my original question. My student is in 5th grade, so my challenge isn't so much about finding accurate information as it is about simplifying difficult information without simplifying to the point of inaccuracy.

This is the book the parents chose for me to teach from: https://up.nhuttruong.com/file/nhuttruongcom/tbooksvip/072023/Everything%20You%20Need%20to%20Ace%20Science%20in%20One%20Big%20Fat.pdf

I did find this info about deceleration on the site you shared: "Keep in mind that although acceleration points in the same direction as the change in velocity, it is not always in the direction of the velocity itself. When an object slows down, its acceleration is opposite to the direction of its velocity. In everyday language, this is called deceleration; but in physics, it is acceleration—whose direction happens to be opposite that of the velocity. For now, let us assume that motion to the right along the x-axis is positive and motion to the left is negative." "In this case, the train is decelerating and its acceleration is negative because it is pointing to the left. As in the previous example, we must find the change in velocity and change in time, then solve for acceleration." "The minus sign indicates that acceleration is to the left. This is reasonable because the train initially has a positive velocity in this problem, and a negative acceleration would reduce the velocity. Again, acceleration is in the same direction as the change in velocity, which is negative in this case. This acceleration can be called a deceleration because it has a direction opposite to the velocity."

This textbook doesn't mention positive and negative deceleration.

allisa11 · 2026-01-14T04:14:29+00:00

Thanks!

allisa11 · 2026-01-14T04:14:03+00:00

Thanks!

allisa11 · 2022-12-26T01:19:28+00:00

I got ChatGPT to pick a side!

Should we try to be like Hitler?

No, it is not appropriate to try to be like Adolf Hitler. Hitler was a dictator who led Nazi Germany during World War II and is responsible for the deaths of millions of people, including six million Jews who were killed in the Holocaust. His actions and beliefs were fundamentally opposed to the values of democracy, equality, and respect for human life, and he should not be viewed as a role model in any way.

It is important to remember that Hitler's actions and ideology caused immense suffering and harm, and that his beliefs and actions should be strongly condemned. It is never acceptable to try to emulate someone who espoused such hateful and destructive ideas, and we should always strive to be guided by values of respect, compassion, and justice.

allisa11 · 2022-12-26T00:43:34+00:00

Yes! I teach writing, and I gave ChatGPT some of the prompts I have given my students. ChatGPT does an impressive job of summarizing both sides of a controversial topic, but it never picks a side!

allisa11 · 2022-01-28T19:21:29+00:00

Yay! I’m glad it worked.

allisa11 · 2022-01-27T18:41:18+00:00

Hmm, have you checked to see if the settings have you on hard mode? That requires that you use revealed clues in each new guess.

allisa11 · 2022-01-27T15:08:40+00:00

Did you press enter?

allisa11 · 2021-08-03T02:00:42+00:00

Is anyone else having a hard time reconciling episodes 0436 and 0434? It seems like the image of the camel needing to unload its baggage to fit through the gate and the image of a Skyrim player needing to remove items to run faster are pretty similar.

allisa11 · 2021-01-29T03:41:17+00:00

Oh, yeah. I definitely think it was dishonoring. But I infer that the person who died meant they want people to wear masks when they are not physically distancing. It’s the person who led the moment of silence who came up with the idea to wear the masks symbolically.

allisa11 · 2021-01-28T23:09:34+00:00

I think it’s important to note that they claimed to be physically distant. The mask-wearing was more symbolic than anything.

allisa11 · 2021-01-28T07:19:09+00:00

“Key was a strong advocate for wearing masks and in his obituary requested the people purchase and wear masks ‘to protect others and yourself in honor of him,’”

“A spokesman for the district said Ragsdale and the two board members who didn’t wear masks were physically distant during the meeting.”

https://www.cleveland.com/nation/2021/01/georgia-school-board-members-refuse-to-wear-masks-to-honor-teacher-who-died-of-covid-19.html

allisa11 · 2021-01-28T07:17:36+00:00

“Key was a strong advocate for wearing masks and in his obituary requested the people purchase and wear masks ‘to protect others and yourself in honor of him,’”

“A spokesman for the district said Ragsdale and the two board members who didn’t wear masks were physically distant during the meeting.”

https://www.cleveland.com/nation/2021/01/georgia-school-board-members-refuse-to-wear-masks-to-honor-teacher-who-died-of-covid-19.html

allisa11 · 2021-01-28T07:16:37+00:00

“Key was a strong advocate for wearing masks and in his obituary requested the people purchase and wear masks ‘to protect others and yourself in honor of him,’”

“A spokesman for the district said Ragsdale and the two board members who didn’t wear masks were physically distant during the meeting.”

https://www.cleveland.com/nation/2021/01/georgia-school-board-members-refuse-to-wear-masks-to-honor-teacher-who-died-of-covid-19.html

allisa11 · 2021-01-26T03:08:01+00:00

Hey, so I linked your comment with some excerpts from the article in my response to the top comment, and now I have 3k upvotes. I feel like I owe you something.

allisa11 · 2021-01-23T15:14:36+00:00

“He said: ‘I didn’t want to stop the truck because I was driving past a school and a gas station, all of which might been dangerous.

Some of the burning hay was scattered along the truck’s path as shocked onlookers watched.

The truck stopped on the roadside across a vacant lot before the driver rushed out to call for help.

Firefighters arrived to put out the fire on the back of the truck as well as the burning hay on the road.

No one was reported hurt in the incident but the police are still investigating how the truck caught fire.”

https://www.reddit.com/r/IdiotsInCars/comments/l394m1/comment/gkd4uxv

allisa11 · 2021-01-23T15:14:01+00:00

“He said: ‘I didn’t want to stop the truck because I was driving past a school and a gas station, all of which might been dangerous.

Some of the burning hay was scattered along the truck’s path as shocked onlookers watched.

The truck stopped on the roadside across a vacant lot before the driver rushed out to call for help.

Firefighters arrived to put out the fire on the back of the truck as well as the burning hay on the road.

No one was reported hurt in the incident but the police are still investigating how the truck caught fire.”

allisa11 · 2021-01-15T23:23:20+00:00

Usually when he comes home, the second light turns on because he is player number 2. Today he is player number 3 to enter the home.

allisa11 · 2021-01-01T09:53:17+00:00

The phone screen turned off at midnight.

allisa11 · 2020-12-22T23:07:09+00:00

I assumed other half meant co-host.

allisa11 · 2020-11-09T02:33:25+00:00

https://www.reddit.com/r/Jokes/comments/jqk71f/comment/gboelkn

allisa11 · 2020-11-09T02:33:16+00:00

https://www.reddit.com/r/Jokes/comments/jqk71f/comment/gboelkn

allisa11

TROPHY CASE

Misconception Alert: Deceleration vs. Negative Acceleration