Forces 2

Contact forces

• active forces (pull, push)
• resistive forces (air resistance, drag, friction)
• tension (stretching)
• compression (squashing)
• reaction (opposes action forces)
• turning force (twist)
• upthrust (upward force from a fluid)

Non-contact forces

Gravitional

• attractive force between objects with a mass (kg)
• the bigger the mass, the stronger the force
• the higher the object, the stronger the force

Magnetic

• attractive/repulsive force between magnetic materials (eg// iron, steel, copper etc)

Electrical

• attractive force between charged materials (+,-)

Scalar or Vector

• scalar only has a magnitude or size (eg// speed, distance, time, mass, temperature)
• vector has size and direction (eg// velocity (2m/s due north), forces, acceleration, momentum)

Resultant Forces

• a resultant force is the single force that has the same effect as the other forces on an object combined
• resultance can change:

1) motion of objects (eg// speed up, slow down)

2) shapes…