5.2 friction

What is the definition of kinetic friction ?

• strength or energy as an attribute of physical action or movement.

• the force that attracts a body towards the centre of the earth, or towards any other physical body having mass.

• a force that acts between moving surfaces

• a type of friction force that acts on a body when there is no relative motion between the object and the surface

What is the definition of Static friction

• a type of friction force that acts on a body when there is no relative motion between the object and the surface

• the Gravitational force with which the Earth attracts the masses towards its center

• the rate of change of velocity.

the coefficient of static friction is____ than the coefficient of kinetic friction

• less

• equal

• more

friction is always___ direction to motion

• opposite

• same

• not related

what dos it mean when the coefficient of static is more than 1?

• fn>ff

• fn<ff

• fn<u

what does the coefficient depend on ?

• type of surface

• normal force

• composition of the material of the surface

• gravity

which of the following

does the friction force depend on?

• type of surface

• weight

• acceleration

• gravity

to determine the___ of a vector, a coordinate system must be chosen

• vector

• static friction

• components

which has the greater coefficient

• kinetic friction

• normal force

• static friction

• acceleration

what is the slope of the line on a kinetic friction force?

• normal force

• static friction force

• coefficient

• coefficient of kinetic friction