Verified answer

Start by setting up a coordinate system where x is parallel to the slope and positive to the right and y is perpendicular to the slope and positive up.

Now draw a free body diagram of the forces that at on the diagram

Fnet=ma

Take these forces and sum up the forces that act in the x direction first

Fx= -mgsin(theta)=ma

You can solve for a now by dividing both sides by mass...notice you don't need to know math for the problem.

a= -gsin(30)= -9.8 * 0.5 = -4.9 m/s^2

Now use the most proper kinematic equation to solve for x final in this case we don't know time, we could solve for it but we don't have to using this one:

V^2=Vo^2+2a(X-Xo)

V=0 m/s since it is stopped Vo=25 m/s X=? Xo=0 a= -4.9 m/s^2

replacing the terms that equal 0 we get and subtracting 2a(X-Xo) since acceleration is negative we get

0=Vo^2-2a(X)

solve for X

2a(x)=Vo^2

x=Vo^2/(2a)

x=25^2/4.9

x=127.6 [m]