Book Store

Download books and chapters from book store.
Currently only available for.
CBSE Gujarat Board Haryana Board

Previous Year Papers

Download the PDF Question Papers Free for off line practice and view the Solutions online.
Currently only available for.
Class 10 Class 12

A man rows a boat with a speed of 18 km/hr in north-west direction. The shore line makes an angle of 15° south of west. Obtain the components of velocity of boat along shore line and perpendicular to shore line.

The velocity of boat is 18 km/hr in N-W direction and shore line makes angle 15° with S of W. Therefore the velocity vector of boat subtends an angle of 60° with shore line.

Component of velocity of boat along shore line =

18 space cos space 60 degree space equals space 9 space km divided by hr.

And component of velocity of boat perpendicular to shore line

<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) #1 /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/lib/com/wiris/util/sys/Store.class.php(56): mkdir('/home/config_ad...', 493) #2 /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/lib/com/wiris/plugin/impl/FolderTreeStorageAndCache.class.php(110): com_wiris_util_sys_Store->mkdirs() #3 /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/lib/com/wiris/plugin/impl/RenderImpl.class.php(231): com_wiris_plugin_impl_FolderTreeStorageAndCache->codeDigest('mml=<math xmlns...') #4 /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/lib/com/wiris/plugin/impl/TextServiceImpl.class.php(59): com_wiris_plugin_impl_RenderImpl->computeDigest(NULL, Array) #5 /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/service.php(19): com_wiris_plugin_impl_TextServiceImpl->service('mathml2accessib...', Array) #6 {main}</pre>

910 Views

A river d km wide is flowing at a rate $straight v subscript 1 straight m divided by straight s.$ A swimmer which can swim with velocity $straight v subscript 2$ relative to water, dives into the river perpendicular to the direction of flow to cross the river. How far he will go down the river along the river?

When the swimmer dives perpendicular to river, then time taken by swimmer to cross the river is,

straight t equals straight d over straight v subscript 2

The distance which the swimmer will go down the river along the river is,

<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) #1 /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/lib/com/wiris/util/sys/Store.class.php(56): mkdir('/home/config_ad...', 493) #2 /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/lib/com/wiris/plugin/impl/FolderTreeStorageAndCache.class.php(110): com_wiris_util_sys_Store->mkdirs() #3 /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/lib/com/wiris/plugin/impl/RenderImpl.class.php(231): com_wiris_plugin_impl_FolderTreeStorageAndCache->codeDigest('mml=<math xmlns...') #4 /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/lib/com/wiris/plugin/impl/TextServiceImpl.class.php(59): com_wiris_plugin_impl_RenderImpl->computeDigest(NULL, Array) #5 /home/config_admin/public/felixventures.in/public/application/css/plugins/tiny_mce_wiris/integration/service.php(19): com_wiris_plugin_impl_TextServiceImpl->service('mathml2accessib...', Array) #6 {main}</pre>

137 Views

Two particles A and B start from P and move along a circular path; in anticlockwise and clockwise direction respectively as shown in above figure. Both the particles are moving with same speed. When will both the particles possess the same average velocities?

The particles are moving along a circular path, but in opposite directions. So, they do not have the same average velocity.

The particles will have the same average velocity, when they are at a point diametrically opposite to each other. Because at this point, both particles will undergo the same displacement in the same time. Hence, at this point the particle will have same velocity.

128 Views

A river 100 m wide is running downwards at the rate of 1 km per hour and a swimmer who can swim at the rate of 3·6 km/hr wishes to reach a point just opposite. Along which direction should he strike and how long will he take to cross the river?

Let the swimmer dive at angle 6 as shown in figure to reach the point B directly opposite to A.
∴

straight v subscript straight m sinθ space equals space straight v subscript straight r

sinθ space equals space straight v subscript straight r over straight v subscript straight m equals fraction numerator 1 over denominator 3.6 end fraction equals 0.278

straight theta equals 16.14 degree

Let the swimmer dive at angle 6 as shown in figure to reach the point

The swimmer should dive at angle (90 + 16·14) =106·14° with the direction of flow. Now time taken to cross the river is,

straight t equals fraction numerator AB over denominator straight v subscript straight m cosθ end fraction equals fraction numerator 0.1 over denominator 36 cross times 16.14 end fraction

equals 0.0289 space hr space equals space 104.1 space straight s

144 Views

What is the displacement of a point on the wheel of radius R initially in contact with ground when the wheel rolls forward half a revolution?

Given,

Radius of the wheel = R

When half revolution is made by the wheel, the point of contact moves from point A to C and hence undegoes the displacement

Distance displaced by the point of contact, AB =

Perpendicular distance traversed by the body = 2R

Therefore, total distance,