Final answer:
The correct choice depends on the canister's context and orientation. Gravity acts on it, the normal force counteracts gravity, friction opposes motion, and tension may exist if suspended. Without specific details, gravity and the normal force are the primary considerations.
Step-by-step explanation:
The question is about the forces acting on a canister and presents options such as gravity, friction, tension, and normal force. To answer this question, it is essential to understand that gravity acts on the canister in a downward direction, giving it weight (W=mg, where m is mass and g is acceleration due to gravity).
The normal force is the support force exerted by a surface against an object resting on it, opposing the force of gravity and acting perpendicular to the surface. If the canister rests on a flat surface without acceleration, the normal force equals the gravitational force but in the opposite direction.
On an inclined surface, the normal force acts perpendicular to the incline and is less than the object's weight. The tendency for an object to slide down an incline creates a frictional force. When no other force is applied, and the system is in equilibrium, the normal force and the force of gravity cancel each other out in the vertical direction, making the net force zero.
Friction, when present, opposes motion and requires a net force to overcome if the object is to move or accelerate. Conversely, in the absence of friction, determining the force required to induce acceleration (F=ma) involves accounting for the gravitational component along the inclined plane and any tension in supporting cords.