If the car went 30 km west in 25 min. and then 40 km east in 35 min., what would be its total displacement?

Question

mrdoe · Answer

Hint: Pythagorean

anonymous · Answer

pythagoren theorem being a2 + b2 = c2? I'm just starting on an assignment that has these problems, but it does not explain how to figure it out? Could you help me with the steps?

mrdoe · Answer

sure, but it's easiest to draw it out until you get the hang of it.  Think about it in terms of Cartesian coordinates.  If the train starts by going 30km west, that's 30km in the -x direction.  Than the train goes east 40km, so this would be 40km in the +x direction.

So actually you would not use the Pythagorean, sorry bout that it's actually even more straightforward, should just be -30 + 40 = 10km (in the +x direction if it is asked)

anonymous · Answer

Ohhhhh, okay! I see how you got that! Using the negative number makes it so much easier!! Hmmm, alrighty! Thank you so much! I'm going to see if I can figure out the rest of the assignment now, thank you again!! (: