Set the river velocity to 2 m/s, boat velocity to 4 m/s and theta to 120°. In this case the boat travels across the stream along the shortest path. This is because |

A) Not for any particular reason. |

B) The sum of velocities of the boat and river is directed towards the other bank. |

C) The velocity of boat has a component opposite river velocity. |

D) The velocity of boat has a component parallel to river velocity. |

For a boat crossing a river to travel the distance between the banks along the shortest path |

A) Boat must have a speed relative to river greater than that of river |

B) Boat can have a speed relative to river less than that of river |

C) Boat can have a speed relative to river equal to that of river |

D) Boat must aim its velocity at right angles to the river velocity |

For a boat crossing a river to travel the distance between the banks along the shortest path |

A) its velocity must be at right angles to the river velocity |

B) its velocity must be at an angle greater than a right angle with the river velocity |

C) its velocity can be at an angle less than a right angle with the river velocity |

D) its velocity can be less than the river velocity |

For a boat crossing a river to travel the distance between the banks along the shortest time |

A) its velocity must be at right angles to the river velocity |

B) its velocity must be at an angle greater than a right angle with the river velocity |

C) its velocity can be at an angle less than a right angle with the river velocity |

D) any of these depending on river velocity |

For a boat crossing a river to travel the distance between the banks along the shortest path |

A) its velocity must be at right angles to the river velocity |

B) its velocity must be at an angle greater than a right angle with the river velocity |

C) its velocity can be at an angle less than a right angle with the river velocity |

D) its velocity can be less than the river velocity |

A boat has to reach a point B on the other bank downstream of the point A it leaves from. This requires |

A) a certain minimum speed if the boat velocity is at along AB |

B) any speed should be all right |

C) minimum speed if the angle is at right angles to the bank |

D) minimum speed if the boat velocity is at right angles to AB |

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