Gravity is a non contact force , jump from a little high place (don't do that :P) , you wont just get stuck in the air you will fall down , this is gravity you dont need any contact
Answer:
oxygen
Explanation:
as it is in the air it can't be depleted or used up
Answer:
C) The function F(x) for 0 < x < 5, the block's initial velocity, and the value of Fr.
Explanation:
Yo want to prove the following equation:

That is, the net force exerted on an object is equal to the change in the kinetic energy of the object.
The previous equation is also equal to:
(1)
m: mass of the block
vf: final velocity
v_o: initial velocity
Ff: friction force
F(x): Force
x: distance
You know the values of vf, m and x.
In order to prove the equation (1) it is necessary that you have C The function F(x) for 0 < x < 5, the block's initial velocity, and the value of F. Thus you can calculate experimentally both sides of the equation.
Answer: momentum has the same direction as that of velocity but when 2 bodies with the same linear momentum & different velocities it has different masses because a vector quantity is represented by a cross product of mass and velocity of object .