Which of the following acts on an object without making contact with it? A)mass B)action-at-a-distance C)weight d)friction

The answer to your question is (b), action-at-a-distance.

Action-at-a-distance is a term used in physics. The idea behind action at a distance is that an object’s position can be changed or moved without actually being touched by another object. For example, this may be done via the force of gravity.

Option (a), mass, is not the answer because mass is a physical property of a substance. Mass is the amount of matter within an object. Mass is not a force that acts upon another object.

Likewise, option (c), weight, is also a physical property. Weight is the measurement of the force exerted on an object by gravity. Although a result of a force, weight is a measurement. It is not an action.

Finally, option (d), friction, is not an option because friction requires contact between two objects. Friction is the resistance an object experiences when it rubs over another object.