Changing the course of an asteroid

[Cret]

Homework Statement

Hello all,

I am really having trouble with following. I want to find the answer myself, but i do not know what equation/s i should apply to solve the problem.

My Question.

How long will it take to deflect an asteroid on a collision course with Earth by attaching a 2000N thruster. I must change the course of the asteroid by 12 Earth diameters. Mass of the Asteroid is 1.3x10^2 kg

Thank you in advance

 

[minger]

You have a distance that needs to be traveled. You have mass and force, so you have acceleration. How would you relate acceleration, distance and time?

 

[Cret]

You have a distance that needs to be traveled. You have mass and force, so you have acceleration. How would you relate acceleration, distance and time?

Thanks for the reply

Presumably I rearrange F=ma to find the acceleration

F = 2000 N
m = mass of asteroid? 1.3x10^12

Since the asteroid has an initial velocity of (20,000 m/s) i suppose i should use the following equation (rearranged to find time):

d=Vi*t+0.5*a*t^2

Where
Vi = initial velocity (20,000 m/s)
a = acceleration (found in the first part)
t = time
d = distance (known)

 

[minger]

No, remember that velocity is a vector, it has both magnitude and direction. Because it says that the astroid is on a collision course, you can assume that the direction is pointed directly towards Earth.

However, you simply want to change the course of it. What is the astroid's velocity in the two directions not towards earth?