Forces (Free Body Diagrams), Free-body Diagram Practice

A sled is being pulled by a rope to the right. The sleds speed is increasing. Diagram the forces acting on the sled

contact forces

applied, friction, air resistance, tension, normal

A toy car is being pushed across a table to the right at a constant speed. Diagram the forces acting on the toy car

applied force

a literal push or pull such as a child pulling a wagon or a worker pushing a crate in a warehouse

A girl is being pulled in a basket to the right by her brother. The speed of the basket is increasing as it is being pulled. Diagram the forces acting on the basket.

friction

always acts in the opposite direction of movement, caused by two surfaces rubbing against one another

A gymnast is hanging onto a bar that is attachted to the celling by two ropes. Diagram the forces acting the bar.

air resistance

also called air friction: upward force that resists the downward force of gravity

A tire swing is hanging by a rope from a tree branch. Diagram the forces acting on the tire.

tension

a pulling force caused by objects connected by a rope or cable

An apple is attached to the celling by a string. A person is pulling the apple towards the ground. Diagram the forces acting on the apple.

normal force

the upward force caused by the surface an object lies upon.. it works in the opposite direction of gravity

A box is being pulled to the left by a person across a table at a constant speed

free body diagrams

simplified diagrams that show the magnitude and direction of forces; longer vector means greater force

A book at rest on top of a table

net force

sum of all forces acting on an object

An acorn falling towards the ground at an increasing speed (motion changing). Do not ignore air resistance

A tennis ball falling torwards the ground. Ignore air friction.

A pet rock is being pulled by a rope to the left. Its speed is increasing (motion is changing) as it moves.

SI unit for force or weight

newton (N)