resultant forces and work done

what is a free body diagram?

a diagram showing all the forces acting on an isolated object

what do the size and direction of arrows represent in a free body diagram?

size represents force magnitude, and direction represents force direction

what is a resultant force?

the overall force acting on an object after combining all individual forces

how do you find the resultant force when forces act in the same direction?

add them together

how do you find the resultant force when forces act in opposite directions?

subtract the smaller force from the larger force

what happens when a resultant force acts on an object?

the object will accelerate in the direction of the force

what is work done?

energy transferred when a force moves an object through a distance

what is the equation for work done?

work done (j) = force (n) × distance (m)

how much work is done when a 20 n force moves an object 20 cm?

4 j

what is one joule of work?

the work done when a 1 n force moves an object 1 m

what happens to energy when work is done against friction?

it is transferred to thermal energy, increasing temperature

what are two types of energy transfer when work is done?

useful (e.g. lifting a load) and wasted (e.g. heat from friction)