Finding the time using the acceleration (forces)

[ilovemynny]

Homework Statement

Joey is now on a raft in the ocean, try to sail home. The raft + Joey have a total mass of 195kg. The ocean current produceds a force of 60N eastwaard and the wind produces a force of 95N at 80 degrees. Find the acceleration of the raft (magnitude and direction). If these forces are constant, how long will it take Little Joey to travel 4km?

Homework Equations

So I figured out the magnitude of acceleration which is 0.62m/s/s and the direction of acceleration is 50.9 degrees.

The Attempt at a Solution

To find Time
would I use this equation: Distance = (0.5)(a)(t^2)
?
if so, would it be

4000m = (0.5)(0.62m/s/s)(t^2)

and just solve t from there?

 

[e.bar.goum]

That seems reasonable, doesn't it?

This probably doesn't belong in the advanced physics section, by the way.

 

[ilovemynny]

awesome :D thank you!

sorry >.< the reason why i put it in advanced is because I'm taking ap physics right now >.< i didn't know where to put it

 

[e.bar.goum]

That's OK. The advanced physics section is for "upper-division (college junior or senior) and graduate-level questions.", so for next time the introductory physics section would be better - you'll get a quicker reply that way, more people read it!

 

[paranormal]

I would first confirm that the given forces are indeed constant. If they are, then I would use Newton's Second Law (F=ma) to calculate the acceleration of the raft, taking into account both the eastward and 80 degree forces. With the magnitude and direction of acceleration, I would then use the kinematic equation d=vt + 0.5at^2 to calculate the time it would take for the raft to travel 4km. It is important to note that this equation assumes constant acceleration, which may not be the case in real-life scenarios. To account for any changes in acceleration, I would need to use a more complex equation, such as d=vt + 0.5at^2 + 0.5j(t^2), where j represents the change in acceleration over time. Overall, it is important to carefully consider the assumptions and limitations of any equations used in solving this problem.