Question #3f1d8

2 Answers

Answer:

If a man is standing by the track and train is running at #60# #km#/#hr# to south his relative velocity is #60# miles south direction.

Explanation:

If he is also running at #10# #km#/#hr# towards south, his velocity relative to train is only #60-10# = #50# #km#/#hr# to south.

If he run to north at #10# #km#/#hr# his relative velocity will be #70# #km#/#hr# with train.
Hope this explains the relative velocity.

May 22, 2016

Answer:

Concept.
For rain problem,
If #vecV_A and vecV_B# are velocities of objects #A and B# respectively then

#vecV_(AB)=vecV_A-vecV_B# is the velocity of #A# with respect to #B#.

Explanation:

Following the above logic

#vecV_(rm)=vecV_r -vecV_m# is velocity of rain with respect to man.

1.bp.blogspot.com
See the vector representation on the right side of the figure above.

  1. Velocity vectors #vecV_m and vec V_r# are drawn.
  2. Recall #-ve# sign in front of the the second term.
    Therefore, draw #-vecV_m# at the tip of #vecV_r#
  3. Join the tail of #vecV_r# to the tip of #-vecV_m# to obtain #vecV_(rm)# as velocity of rain with respect to man.

Similar steps need to be followed if #vecV_(mr)#, velocity of man with respect to rain is to be found.

  1. Velocity vectors #vecV_m and vec V_r# are drawn.
  2. We are to find out #vecV_(mr)#, velocity of man with respect to rain.
    We know that #vecV_(mr)=vecV_m-vecV_r#
    Therefore draw #-vecV_r# at the tip of #vecV_m#
  3. Join the tail of #vecV_m# to the tip of #-vecV_r# to obtain #vecV_(mr)# as velocity of man with respect to rain.