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Motion In A Plane

Question
CBSEENPH11018623

Rain is falling vertically with speed of 30 m/s. A woman rides a bicycle with a speed of 10 m/s in N to S direction. In which direction she should hold the umbrella?

Solution

Let stack straight v subscript straight r with rightwards arrow on top be the velocity of rain and <pre>uncaught exception: <b>mkdir(): Permission denied (errno: 2) in /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/lib/com/wiris/util/sys/Store.class.php at line #56mkdir(): Permission denied</b><br /><br />in file: /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/lib/com/wiris/util/sys/Store.class.php line 56<br />#0 [internal function]: _hx_error_handler(2, 'mkdir(): Permis...', '/home/config_ad...', 56, Array)
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#6 {main}</pre> be the velocity of the woman.
                 
To the woman the rain will appear to be coming from the direction of stack straight v subscript straight r with rightwards arrow on top minus straight v with rightwards arrow on top. 
Therefore, woman should hold the umbrella in the direction of left parenthesis stack straight v subscript straight r with rightwards arrow on top minus straight v with rightwards arrow on top right parenthesis which is given by, 
            space space space space tanθ equals straight v over straight v subscript straight r equals 10 over 30 equals 1 third
i.e. she should hold the umbrella at an angle straight theta equals tan to the power of negative 1 end exponent left parenthesis 1 divided by 3 right parenthesis south of vertical.