# Question #0ed3c

##### 1 Answer

Aug 15, 2015

Huck's speed *relative* to the river bank is

#### Explanation:

The idea behind this problem is that Huck's walking **perpendicular** to the direction of the raft, which is parralel to the river bank.

This means that Huck's speed **relative to the shore** will have **two components**, one parralel to the shore and one perpendicular to the shore.

This means that you can use Pythagoras' Theorem to find the *magnitude* of Huck's velocity, i.e. his speed

#v_"Huck"^2 = v_"parallel"^2 + v_"perpendicular"^2#

#v_"Huck" = sqrt(v_"parralel"^2 + v_"perpendicular"^2)#

If Huck is moving **perpendicular** to the shore and **parralel** to the shore, then you can say that

#v_"Huck" = sqrt(1.70^2"m"^2/"s"^2 + 0.60^2"m"^2/"s"^2)#

#v_"Huck" = color(green)("1.80 m/s")#