Vectors - velocity is changing but speed is not

[kenji1992]

Vectors -- velocity is changing but speed is not...

Homework Statement

Which pair of vectors represent an object whose velocity is changing but whose speed is NOT changing?

Homework Equations

The Attempt at a Solution

E? V is going left, indicating negative, while acceleration goes in the other direction.

 

[NascentOxygen]

E? V is going left, indicating negative, while acceleration goes in the other direction.

But that acceleration is going to change the speed. It will, initially, decrease the speed. E is not correct.

 

[kenji1992]

#C, D, E can't be correct then by that logic... I hope I'm interpreting that correctly.

 

[haruspex]

#C, D, E can't be correct then by that logic... I hope I'm interpreting that correctly.

Right... and one more - which?