# How exactly does a dynamicist define deceleration in this case?

• gikiian
In summary, the conversation revolves around the definition of deceleration in a dynamicist's perspective and the confusion around whether it refers to the tangential component or the total vector. The general assumption is that the total vector is implied, but clarification may be needed in certain cases.
gikiian
Hey friends. I wanted to know how exactly would a dynamicist define deceleration of a car on a road with humps and dips. Actually I always thought that deceleration of car on the road will be the vector a (see the diagram), however, in a sample problem in my dynamics book, it the car's deceleration is taken as the vector a_t (see the diagram), but it is not explicitly mentioned to be the tangential component. So how do we differentiate between the two cases?

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First off, dynamicists usually speak in terms of acceleration, rather than deceleration.

You question seems to revolve around whether the term refers to the tangential component or the total vector. Unless otherwise specified, I would usually assume that the total vector is implied, but anytime there seems to be confusion, the only option is to ask for clarification.

I believe what you're saying is correct. Thanks!

## 1. What is deceleration?

Deceleration is the rate at which an object's velocity decreases over time. It is the opposite of acceleration, which is the rate at which an object's velocity increases.

## 2. How does a dynamicist define deceleration?

A dynamicist defines deceleration as the negative change in an object's velocity divided by the time interval in which the change occurs. It is typically measured in meters per second squared (m/s^2).

## 3. What factors can affect deceleration in a given case?

Deceleration can be affected by a number of factors, including the object's mass, the force acting upon it, and any external forces such as friction or air resistance.

## 4. How does deceleration differ from negative acceleration?

Deceleration and negative acceleration are often used interchangeably, but technically they are not the same. Deceleration specifically refers to a decrease in velocity, while negative acceleration can refer to either a decrease or an increase in velocity in the opposite direction of the initial motion.

## 5. Can deceleration ever be positive?

No, deceleration is always a negative value since it represents a decrease in velocity. However, depending on the direction of motion, it can be written as either a positive or negative number.

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