Question

a force f is applied on an object and its displaced by the distance d give expression for work done when angle between force and displacement are degree (i) 0 degree (ii) 180 degree specify whether the work done is positive or negative in each case

Answer 1

1) WORK DOME +VE

  FORCE =MASS x ACCLERATION SIN 0           (SIN 0=1)

2)WORK DONE -VE

  FORCE =MASS x ACCLERATION SIN 180           (SIN 180=-1)

Answer 2

w= fd cos0°
w= fd becoz = cos0°=1

w=fd

if cos180°
w=fd cos180°
cos180°=0
w=0
becoz f is going opposite that mean here is work not happen