Question

Question 19
please answer its urgent​

Answer 1

Explanation:

1)Work is defined as to put forth effort in order to accomplish something or to have a job. ...(classic definition of work)

Work is defined as a energy transfer of a body when particle move over a displacement in the direction of applied external force(modern definition of work)

2)SI unit of Work is Joule(J)

3)As I tell u in modern definition.. works is performed when displacement and external force having same direction..but if u see in Q. displacement and force are perpendicular to each other so work done is zero

4)Work done=Force * Displacement Cos©

(mathematical expression)

where © is angle between force and displacement

as u see in Q the angle between force and displacement is 90..

so

cos 90°=0

so work done is zero (mathematical expression for point no 3)