Question
A truck and car are both moving with same kinetic energy and brought to rest by applying brakes. The brakes give equal retarding forces to both the vehicles. Which of the two vehicles come to rest after travelling shorter distance?
Solution
When brakes are applied, the frictional forces start acting on the drum of the wheel.
If F is the force of friction and s is the distance travelled by truck or car, then work done against force of friction is at the cost of kinetic energy of vehicles.
That is, work done
i.e.
∴![<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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Since kinetic energy and the retarding force on both the vehicles are same, therefore both will come to rest after travelling equal distances.
If F is the force of friction and s is the distance travelled by truck or car, then work done against force of friction is at the cost of kinetic energy of vehicles.
That is, work done
i.e.
∴
Since kinetic energy and the retarding force on both the vehicles are same, therefore both will come to rest after travelling equal distances.
