Basic force question(should be too easy)

[aaquib]

Homework Statement

A supertanker of mass 1.0 X 10^8 travels 3.5km, reaching a speed of 4.1km/h from rest. What was the magnitude of the unbalanced force acting on it?


2. The attempt at a solution

I got the acceleration(2.4m/s^2), but how do I fit this into the equation? The answer is 18529.5N, but I have no idea how they got that.

 

[Snazzy]

$$W=\Delta KE$$

 

[aaquib]

$$W=\Delta KE$$

I've only taken physics for 2 months in my life, so please excuse me, but what the heck is W and what the heck is KE?

 

[Snazzy]

W is work, KE is the kinetic energy.

 

[aaquib]

W is work, KE is the kinetic energy.

Im not used to using that formula. I usually use force=mass X acceleration.

 

[Snazzy]

Well, your acceleration is wrong, possibly due to the fact you forgot to convert units.