If F applied is 17 Newtons to the right, what is the magnitude and direction of the friction force, if the object is traveling with the constant velocity? Find friction force and its direction

There's some missing context here, but I would guess you're talking about a box or something with some mass m being pushed over a flat surface. Since it's moving with constant velocity, there is no acceleration and so the box is in equilibrium. In particular, the horizontal forces cancel each other. If f is the magnitude of the friction force, then

17 N + (-f ) = 0

f = 17 N

and this force points opposite the direction of motion.

D

Explanation:

F=ma

F of 5 kg rock = 49N

F of 10 kg rock = 98 N

Divide by respective masses to get acceleration, and of course you will get 9.8 m/s^2 for both.

Now, use potential energy equals kinetic energy. mgh=(1/2)mv^2 mass cancels out of the equation, since it's on both sides, so we can stop right there. We have algebraically determined that mass does not affect acceleration or velocity!

Hope this helped.