Physics > Motion in One Dimension > 9.0 River boat problem
Motion in One Dimension
1.0 Introduction
2.0 Kinematic variables
2.1 Distance and displacement
2.2 Average speed and velocity
2.3 Instantaneous speed and velocity
2.4 Average and instantaneous acceleration
3.0 Motion in one dimension
3.1 Motion in a straight line with uniform velocity
3.2 Motion in a straight line with uniform acceleration
3.3 Motion in a straight line with non-uniform acceleration
4.0 Derivation of the kinematics equation
5.0 Vertical motion under gravity
5.1 Basic terminologies for motion under gravity
5.2 Detailed concept of motion under gravity
5.3 Solved examples
6.0 Analysis of motion through graph
6.1 Displacement - time graph
6.2 Velocity - time graph
6.3 Area under the graph
6.4 Solved examples
7.0 Relative motion
7.1 Relative displacement
7.2 Relative velocity
7.3 Relative acceleration
7.4 Illustration of relative motion
7.5 Application of relative motion
8.0 Simultaneous motion of two bodies
9.0 River boat problem
9.1 Downstream
9.2 Upstream
9.3 Crosses the river in shortest interval of time
9.4 Reaches the point just opposite from where he started
9.5 River-man problem
9.6 Solved examples
10.0 Aircraft-wind problem
11.0 Rain problem
9.5 River-man problem
2.2 Average speed and velocity
2.3 Instantaneous speed and velocity
2.4 Average and instantaneous acceleration
3.2 Motion in a straight line with uniform acceleration
3.3 Motion in a straight line with non-uniform acceleration
5.2 Detailed concept of motion under gravity
5.3 Solved examples
6.2 Velocity - time graph
6.3 Area under the graph
6.4 Solved examples
7.2 Relative velocity
7.3 Relative acceleration
7.4 Illustration of relative motion
7.5 Application of relative motion
9.2 Upstream
9.3 Crosses the river in shortest interval of time
9.4 Reaches the point just opposite from where he started
9.5 River-man problem
9.6 Solved examples
River-man problem is same as river-boat problem. Instead of the boat when a man is swimming it is known as a river-man problem.
| River-boat | River-man |
| $v_B:$ Absolute velocity of boat $v_{BR}:$ Velocity of boat wrt river or actual capacity of boat engines $v_R:$ Velocity of river | $v_M:$ Absolute velocity of man $v_{MR}:$ Velocity of man wrt river or actual capacity of man to swim $v_R:$ Velocity of river |
| We know, $${\overrightarrow v _{BR}} = {\overrightarrow v _B} - {\overrightarrow v _R}$$$${\overrightarrow v _B} = {\overrightarrow v _{BR}} + {\overrightarrow v _R}$$ | Similarly, $${\overrightarrow v _{MR}} = {\overrightarrow v _M} - {\overrightarrow v _R}$$$${\overrightarrow v _M} = {\overrightarrow v _{MR}} + {\overrightarrow v _R}$$ |
| Note: All the cases of river-boat problem is applicable in river-man problem. | |
