# Homework Help: Initial Acceleration?

1. May 29, 2010

### DriverX

Initial Acceleration???

The force exerted by the wind on a sailboat is approximately perpendicular to the sail and proportional to the component of the wind velocity perpendicular to the sail. For the 950-kg sailboat shown in the figure below, the proportionality constant is

Water exerts a force along the keel (bottom) of the boat that prevents it from moving sideways, as shown in the figure. Once the boat starts moving forward, water also exerts a drag force backwards on the boat, opposing the forward motion.

If a 15-knot wind (1 knot = 0.514 m/s) is blowing to the east, what is the initial acceleration (m/s2) of the sailboat?

2. May 30, 2010

### tiny-tim

Welcome to PF!

Hi DriverX! Welcome to PF!

But … is that picture really a sailboat?

It looks more like a horse!

3. May 31, 2010

### DriverX

Re: Initial Acceleration???

4. May 31, 2010

### tiny-tim

that's better!

ok …
… so find the force exerted by the wind perpendicular to the sail, and so find the forward force, and use F = ma.

What do you get?

5. May 31, 2010

### vorcil

Re: Initial Acceleration???

Driver
because a force is a vector and the question is in two dimensions, i.e X and Y,
you can separate the force into it's x and y components

e.g if you push a block north east (like your sail) at an angle of 45 degrees
your F vector, is really two forces, one going east in the X direction, and one going north in the Y direction,

so the Feast = Fcos45 degrees
and Fnorth = Fsin45 degrees

you can use this concept (i think? ) to help solve your question