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## Homework Statement

the position vecter

**r**of a particle at a time t is

**r**=

**i**cos t +

**j**sin t +

**k**t show that the magnitudes of the velocity and acceleration vectors are constant. Describe the motion

## The Attempt at a Solution

velocity =

**i**(-sint) +

**j**(cost) +

**k**

magnitude is [tex]\sqrt{(-sint)^2 + (cost)^2 + 1}[/tex] = [tex]\sqrt{2}[/tex]

acceleration =

**i**(-cos t) -

**j**(sin t)

magnitude is [tex]\sqrt{(-sint)^2 + (-cost)^2 }[/tex] = [tex]\sqrt{1}[/tex] = 1

but I am not sure how to discribe the motion, at first i was thinking of an object moving at a constant velocity of [tex]\sqrt{2}[/tex] and to move at a constant velocity it acceleration isn't changing so should that not mean the acceleration is 0 instead of 1?