# Question 0ed3c

Aug 15, 2015

Huck's speed relative to the river bank is $\text{1.8 m/s}$.

#### 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

${v}_{\text{Huck"^2 = v_"parallel"^2 + v_"perpendicular}}^{2}$

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

If Huck is moving $\text{0.60 m/s}$ perpendicular to the shore and $\text{1.70 m/s}$ 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")#