How do I find how far object slides before it stops without it's mass?

I'm assuming that the object is sliding on a horizontal surface.

The normal (weight) force due to the object is mg where m is the mass and g is the acceleration due to gravity.

By definition, the Friction force F = umg where u is the coefficient of kinetic friction.

But the friction force F is the force decelerating the object

From Newton's 2nd Law:

F = mass * a where a is the acceleration

Therefore ma = umg (divide by m and m disappears)

a = ug = 0.46 * 9.81 = 4.513 m/s^2

You know initial velocity u = 4.0 m/s

final velocity v = 0

deceleration a = - 4.513 m/s^2

v^2 = u^2 + 2ax

0 = 16 - 9.026x

x = 16/9.026 = 1.77m

Good luck.

you also need acceleration (gravity) a=9.81 m/s2 and you need the angle of the slope