osker246
Jul17-08, 12:50 AM
1. The problem statement, all variables and given/known data
Mary needs to row her boat across a 100 m wide river that is flowing to the east at a speed of 1.0 m/s. Mary can row the boat with a speed of 2.0 m/s relative to the water.
2. Relevant equations
pythagorean theorem: a^2+b^2=c^2
3. The attempt at a solution
Ok so I know this is pretty straight forward problem. But the 100 m is throwing me off here. I draw a vector diagram and add the two component vectors:
(1,0)
+(0,2)
------
(1,2)
Now i used pythagorean theorem to find the resultant 1^2 + 2^2 = R^2, in which R=5^1/2=2.2. So she's moving accross the river at a rate of 2.2 m/s. Now I'm not sure how 2.2 m/s and 100 m finds her displacement. Any tips?
Mary needs to row her boat across a 100 m wide river that is flowing to the east at a speed of 1.0 m/s. Mary can row the boat with a speed of 2.0 m/s relative to the water.
2. Relevant equations
pythagorean theorem: a^2+b^2=c^2
3. The attempt at a solution
Ok so I know this is pretty straight forward problem. But the 100 m is throwing me off here. I draw a vector diagram and add the two component vectors:
(1,0)
+(0,2)
------
(1,2)
Now i used pythagorean theorem to find the resultant 1^2 + 2^2 = R^2, in which R=5^1/2=2.2. So she's moving accross the river at a rate of 2.2 m/s. Now I'm not sure how 2.2 m/s and 100 m finds her displacement. Any tips?