Velocity, Speed, and Acceleration?

Question

I am extremely confused between these velocity, speed, and acceleration.

1. If velocity is negative and acceleration is positive, then speed is ______?
2. If velocity is positive and speed is decreasing, then acceleration is ______?
3. If velocity is positive and decreasing, then speed is _____.
4. If speed is increasing and acceleration is negative, the velocity is _____ and _____?
5. If velocity is negative and increasing, then speed is _____?

Any help would be appreciated.

Answer 1

1. decreasing.

V is becoming less negative so the SIZE of the velocity ( speed ) is becoming less.



2.Negative

The speed is decreasing meaning that the size of the velocity is getting less and the velocity is positive so we are getting less positive velocity. ie a negative change.



3. decreasing. The size of the velocity is becoming smaller.



4. negative and decreasing. But the terms are confusing.

the speed is getting larger so the size of the velocity is becoming bigger. i.e a larger number.

But the only way that a bigger number represents a smaller quantity is if that number is negative

ie -23 < - 20 even though 23 > 20



5. decreasing.

so imagine the velocity at - 23 . A little later it is only -20 that is increasing the velocity.

But the magnitude ( size ) is 20 which is smaller than a size of 23

Answer 2

1. decreasing.

2. negative.

3. decreasing.

4. negative and increasing.

5. increasing.



Speed only has magnitude which means that it is never negative or positive.

Velocity is basically speed with direction (it can be positive or negative).

Acceleration is how fast the velocity is changing and it also has direction.



Given these rules, if velocity and acceleration ever have opposite signs, then the speed is slowing down. And if the velocity and acceleration have the same signs, the speed will be increasing.

Answer 3

Velocity and acceleration are vector quantities

This means they have both magnitude and direction.

Velocity is a speed in a specific direction

acceleration can change a velocity either by changing the magnitude (if the direction is the same (increase in magnitude) or in exactly the opposite direction (decrease in magnitude) or by changing the direction (the magnitude might be the same, but the direction changes)



Speed is often confused with velocity

Answer 4

hey

let us think in that way

if u r going in positive X direction then u define speed as +V

and u differentiate this velocity at any point of time then if acceleration come positive then u will say speed is increasing



now if you r going in negative X direction then u have to define V as -V

and after differentiating this V if u end up with negative acceleration then again u will say speed is increasing

+V and + A means speed is increasing

-V and -A means speed is increasing

+V and -A means speed is decreasing

-V and +A means speed is decreasing

Answer 5

Can Velocity Be Negative