Chadwick is pushing a piano across a level floor. The piano can slide across the floor without friction. If Chadwick applies a horizontal force to the piano, what is the piano's acceleration?
Identify the forces acting on the object of interest. From the list below, select all the forces that act on the piano.

a. Acceleration of the piano
b. Gravitational force acting on the piano (piano's weight)
c. Speed of the piano
d. Gravitational force acting on Chadwick (Chadwick's weight)
e. Force of the floor on the piano (normal force)
f. Force of the piano on the floor
g. Force of Chadwick on the piano
h. Force of the piano pushing on Chadwick

In this case, as the floor is level (which it means that the piano is at rest in the vertical direction) and the floor is frictionless, the only net force on the piano ir the horizontal force applied to the piano.

According to Newton's 2nd Law, this acceleration is proportional to the force applied, being the proportionality constant the mass of the piano:

Fnet = m*a

Solving for a:

a = F/mp

There are three forces acting on the piano, two vertically and one horizontally.

The vertical forces are the gravitational force (downward), and the normal force, which is the force of the floor on the piano. The only other force is the force applied by Chadwick pushing on the piano, which is the only responsible for the acceleration of the piano.