Under what conditions is the work done called positive,negative and zero work?Give ONE example each of positive and negitive work.
Work done W depends on two factors
1. Applied Force
Since Displacement is vector quantity . So it depends on dirction and magnitude.
Mathematically we can define
where F is force , S is displacement and `theta` angle or direction.
If `theta=0` ie. force applied and object displaced in direction of force.
work done is positive and maximum. e. g. Pushing an object
If `theta=90^o` ,body displaced in perpendicular direction of force
work done is zero. Carry load doing work against gravity but displacement is perpendicular.
work done is negative. body displace in direction opposite to force.