Find the resultant displacement from the cave entrance

[hawk24]

Homework Statement

While exploring a cave, a spelunker starts at the entrance and moves the following distances. She goes 75 m north, 250 m east, 100 m at an angle 30° north of east, and 160 m south. Find the resultant displacement from the cave entrance.

Homework Equations

The Attempt at a Solution

So (75+100sin30- 160) = -35
and 250 + 100cos30 = 336.6025
magnitude =338.4173

Trying to find the angle and should be arctan(-35/336.6025)=-5.93629

Here's my problme though I accidently used 150 m south and blackboard gave me credit for 335.6729 m as my magnitude. Now who is wrong me or blackboard? I'm at lost as to which numbers to use now for my angle calculation.

 

[tiny-tim]

hi hawk24!

i'm surprised it didn't reject your answer as having too many sig figs …

maybe the correct answer is 340?