# Homework Help: Velocity of a ladybug relative to the ground

1. Apr 13, 2012

### TheronSimon

1. The problem statement, all variables and given/known data
A ladybug with a velocity of 10 mm/s [W] crawls on a chair that is being pulled with a velocity of 40 mm/s [40 degrees N of W]. What is the velocity of the ladybug relative to the ground?

2. Relevant equations

3. The attempt at a solution
finding the y-component
40(sin40) = 25.7

x-component requires the addition of two x-axis component vectors
40cos40 + 10 = 40.6

Now a² + b² = c²
25.7² + 40.6² = c²
c = 48.1mm/s

2. Apr 13, 2012

### tiny-tim

Hi TheronSimon!
looks ok

now you just need to state the direction of the velocity

(btw, maximum 2 significant figures in this case )

3. Apr 14, 2012

### TheronSimon

so for the direction tan -1 (25.7/40.6) = 32'

so the complete answer is 48 mm/s [W32'N] ?

4. Apr 14, 2012

### tiny-tim

yes

(probably best to call it "32° N of W", same as in the question )

(btw, you'll find a ° in the Quick Symbols box on the right of the Reply box)

5. Apr 14, 2012

### TheronSimon

alright thank you very much Tim! :)