Question

unit 2 test: forces and motion (10/15)
which of the following is not a contact force?
friction
fluid forces
gravity
elastic forces

Explanation:

• Friction: It occurs when two surfaces are in contact and rub against each other. So, it is a contact force.
• Fluid forces: These act on an object when it is in contact with a fluid (liquid or gas). For example, drag force on a swimmer in water. So, it is a contact force.
• Gravity: It is a non - contact force. It is the force of attraction between two objects with mass, and it acts at a distance. For example, the Earth pulls an apple towards it without any physical contact.
• Elastic forces: These occur when an object is deformed (stretched or compressed) and it tries to return to its original shape. This deformation requires contact. For example, the force exerted by a stretched spring. So, it is a contact force.

Answer:

gravity