## How can an object accelerate without changing its speed?

Ch.

An **object’s** acceleration is the rate **its velocity** (**speed** and direction) changes. Therefore, an **object can accelerate** even if **its speed** is constant – if **its** direction changes. If an **object’s velocity** is constant, however, **its** acceleration will be zero.

## Can an object be accelerating if it isn’t speeding up or slowing down?

A person **can** be moving very fast and still not be **accelerating**. **Acceleration** has to do with changing how fast an **object** is moving. **If** an **object** is not changing its velocity, then the **object** is not **accelerating**.

## Can a particle have acceleration without speed?

– J. Yes, it’s possible to **have** zero **speed** while **accelerating**, but only for an instant. **Acceleration** is the rate at which an object’s **speed** and direction are changing with time, so whenever an object passes through zero **speed** as it reverses directions it **has** a non-zero **acceleration** but a **speed** of zero.

## Can an object accelerate when its speed is constant?

An **object can** in fact **accelerate** if **its speed is constant**. The catch is, by definition the **speed** will stop being **constant** the instant an **object** starts **accelerating**. You cannot have both, but an **object can** go from a constent **speed** to acceleration.

## Can one speed negatively?

No, **speed** cannot be **negative**. Since **speed** is a scalar quantity and doesn’t have a direction. Velocity on the other hand, **can** be **negative**.

## Can speed be constant while acceleration is not zero?

Yes it is possible for **speed** to be **constant while** the **acceleration is not zero**. **Speed** is the magnitude of the velocity vector. Unlike the velocity, which is vector quantity, the **speed** is a scalar quantity. As such, the **speed** only has magnitude.

## Does a negative acceleration always mean an object is slowing down?

If you **always** choose the current direction of motion as positive, then an **object** that is **slowing down** will **always** have a **negative acceleration**.

## Can a body have uniform speed but still have acceleration?

(i) A **body can have acceleration** even when it **has uniform speed**. A **body** in **uniform** circular motion **has uniform speed but** at every point its direction of **velocity** changes, so its motion is **accelerated**. (ii) Yes, a **body can have acceleration** even when its **velocity** is zero.

## Can Objects at rest accelerate?

Yes, **acceleration** is a change in velocity, so an **object** might be momentarily at **rest** but a split-second later have some speed, i.e. it **can** be changing its velocity even if it is momentarily at **rest**. An example is a vertically thrown ball at the top of its trajectory, or a yo-yo just as it turns around.

## Does 0 velocity mean 0 acceleration?

Yes indeed. Derivative of **velocity** with respect to time **is acceleration**. That **means** if accelerations **is zero**, **velocity** must be constant. Also if the **velocity is 0**(which **is** itself a constant) also indicates that **acceleration is zero**.

## When velocity is 0 What is acceleration?

so if the **velocity** does not change with time the **acceleration** is necessarily zero. Since in your example the **velocity** is constant during the interval that means dv/dt= and therefore that a= during the interval.

## Why is acceleration not zero when velocity is zero?

For the most part **velocity** is **not zero** if an object is **accelerating**. Since **acceleration** is the change in **velocity** over time, there has to be a change in **velocity** for something to **accelerate**. If the **velocity** is constant however, the **acceleration** is **zero** (because the **velocity** isn’t changing over time).

## Can speed of a object is justify?

**Speed** = Distance travelled/Time taken

The ratio of distance travelled and the time taken by a body **can** be zero but not negative. Since distance and time are positive quantities and **speed** is obtained by the ratio of these two quantities, **speed** cannot be negative.

## Can an object be accelerated?

An **object** which experiences either a change in the magnitude or the direction of the velocity vector **can** be said to be **accelerating**. This explains why an **object** moving in a circle at constant speed **can** be said to **accelerate** – the direction of the velocity changes.

## What is constant speed?

An object is travelling at a steady or **constant speed** when its instantaneous **speed** has the same value throughout its journey. For example, if a car is travelling at a **constant speed** the reading on the car’s speedometer does not change.