JEE Main2004MathematicsHeights and DistancesActual
A particle moves towards east from a point A to a point B at the rate of 4 ~km / h and then towards north from B to C at the rate of 5 ~km / h . If A B=12 ~km and B C=5 ~km , then its average speed for its journey from A to C and resultant average velocity direct from A to C are respectively
Options
- A17 4 ~km / h and 13 4 ~km / h
- B13 4 ~km / h and 17 4 ~km / h
- C17 9 ~km / h and 13 9 ~km / h
- D13 9 ~km / h and 17 9 ~km / h
Correct answer
A. 17 4 ~km / h and 13 4 ~km / h
Step-by-step solution
Time T₁ from A to B= 12 4 =3 hrs T₂ from B to C= 5 5 =1 hrs . Total time =4 hrs . Average speed = 17 4 ~km / hr . Resultant average velocity = 13 4 ~km / hr .