CBSE Class 12-science Answered
A boat with a speed of 5 km/hr in still water crosses a river of width one km along the shortes possible path in 15 minutes.
Find the velocity of river current in km/hr.
Asked by | 02 Apr, 2013, 10:46: AM
Expert Answer
In still water,
Distance=1km
Speed , s=5km/hr
So, Time taken = 1/5 hr
In the flowing river,
Distance = 1km as the boat is supposed to take the shortest route (directly opposite)
Time = 15 min = 15/60hr =1/4 hr
Resultant speed of boat in river , u = 1/(1/4) = 4 km/hr
Let the speed of river be v
Using pythagoras theorem in the velocity triangle
u^2=s^2-v^2
4^2=5^2-v^2
v=3km/hr
Distance=1km
Speed , s=5km/hr
So, Time taken = 1/5 hr
In the flowing river,
Distance = 1km as the boat is supposed to take the shortest route (directly opposite)
Time = 15 min = 15/60hr =1/4 hr
Resultant speed of boat in river , u = 1/(1/4) = 4 km/hr
Let the speed of river be v
Using pythagoras theorem in the velocity triangle
u^2=s^2-v^2
4^2=5^2-v^2
v=3km/hr
Answered by | 03 Apr, 2013, 02:03: AM
Concept Videos
-
Properties of Inverse Trigonometry Part - 1
This video explains the properties of inverse trigonometric applications an... -
Graphical representation of inverse trigonometric funct ...
Graphical representation of inverse trigonometric functions and principle ... -
Properties of Inverse Trigonometry Part - 2
This video covers the properties of inverse trigonometric applications and ... -
Introduction to inverse trigonometric functions
This video covers examples related to finding the principle value of these ... -
Problem-solving on inverse trigonometric applications ...
Understand the properties of inverse trigonometric applications and their u...
CBSE 12-science - Maths
Asked by sahrudadayajena | 27 Jan, 2024, 09:11: PM
ANSWERED BY EXPERTCBSE 12-science - Maths
Asked by rajashekararishu | 05 Jan, 2024, 09:31: PM
ANSWERED BY EXPERTCBSE 12-science - Maths
Asked by ambigamagendran256 | 04 Nov, 2023, 05:43: AM
ANSWERED BY EXPERTCBSE 12-science - Maths
Asked by gopalkumarrai87 | 11 Oct, 2023, 11:02: AM
ANSWERED BY EXPERT
CBSE 12-science - Maths
Asked by sdmbotch1123 | 10 Apr, 2023, 10:55: PM
ANSWERED BY EXPERTCBSE 12-science - Maths
Asked by varma.renu9481 | 13 Mar, 2023, 11:51: AM
ANSWERED BY EXPERTCBSE 12-science - Maths
Asked by w3ctiger | 12 Feb, 2023, 11:55: AM
ANSWERED BY EXPERTCBSE 12-science - Maths
Asked by joymaibam38 | 26 Dec, 2021, 09:04: AM
ANSWERED BY EXPERTCBSE 12-science - Maths
Asked by amansharma08116 | 14 Jul, 2021, 09:37: AM
ANSWERED BY EXPERT
