Question

Explain (i) Work is positive . (ii) Work is negative (iii) Work is zero

Answer 1

work is said to be positive when the angle will be obtuse.
work is said to be negative when angle will acute.
last work is said to zero when angle will be 90degree or when the force applied but body doesn't displaces

MUST MARK AS BRAINLIEST

Answer 2

Answer:

POSITIVE WORK: The work done on an object is said to be positive work when force and displacement are in same direction.

Example: When an object moves on horizontal surface, force and displacement acts in same direction. So, work done is positive.

NEGATIVE WORK: The work done is said to be negative work when force and displacement are in opposite direction.

Example: When an object is thrown upwards,the force of gravity is in downward direction whereas displacement acts in upward direction.  

ZERO WORK: The work done is said to be zero when force and displacement are perpendicular to each other or when either force or displacement is zero.

Example: When we hold an object and walk, the force acts in downward direction whereas displacement acts in forward direction.