Answer:
gravitational force acting on the piano (piano's weight)
force of the floor on the piano (normal force)
force of Chadwick on the piano
Explanation:
There is a missing part to this question - found on google:
"Chadwick is pushing a piano across a level floor. The piano can slide across the floor without friction. Chadwick applies a horizontal force to the piano.
Identify the forces acting on the object of interest. From the list below, select all the forces that act on the piano.
acceleration of the piano
gravitational force acting on the piano (piano's weight)
speed of the piano
gravitational force acting on Chadwick (Chadwick's weight)
force of the floor on the piano (normal force)
force of the piano on the floor
force of Chadwick on the piano
force of the piano pushing on Chadwick"
Solution:
We have only three forces acting on the piano:
- The horizontal push, which is applied by Chadwick, and which is responsible for the piano accelerating along the floor
- The weight of the piano, [tex]W=mg[/tex] (where m= mass of the piano and g=acceleration of gravity), acting downward. The force of gravity is always present for object on the Earth's surface
- The normal reaction of the floor on the piano, N, which is equal in magnitude and opposite in direction to the force of gravity
So the only choices in the list that are correct are:
gravitational force acting on the piano (piano's weight)
force of the floor on the piano (normal force)
force of Chadwick on the piano
The other choices are wrong because:
- The speed of the piano and the acceleration of the piano are not forces
- The forces acting on Chadwick are not acting on the piano, so we don't consider them
- The forces acting on the floor are not acting on the piano, so we also don't consider them
