Algebra.Com's Answer #819885 by ikleyn(52794)![\"\"](\"/images/stars/stars-13.gif\")  
You can put this solution on YOUR website!
.
\n" );
document.write( "A body  SLIDES down  AT incline plane which  MAKES angle of 30° with the horizontal.
\n" );
document.write( "Neglecting friction, calculate
\n" );
document.write( "a) The velocity of the body after sliding 10m from rest.
\n" );
document.write( "b) The time taken to slide 10m distance.
\n" );
document.write( "~~~~~~~~~~~~~~~~\r
\n" );
document.write( "
\n" );
document.write( "
\n" );
document.write( "\n" );
document.write( " Pay your attention on how I edited your post, making punctuation correct, in order for the post would have sense.\r
\n" );
document.write( "
\n" );
document.write( "
\n" );
document.write( "\n" );
document.write( "\r\n" );
document.write( "(a) Notice that the height \"h\" is half of the hypotenuse, since the angle with horizont is 30.\r\n" );
document.write( "\r\n" );
document.write( " So, the height is  = 5 meters.\r\n" );
document.write( "\r\n" );
document.write( " The change of the potential energy between the levels h = 5 meters and h = 0 if P = mgh,\r\n" );
document.write( "\r\n" );
document.write( " where m is the mass of the body in kilograms and h = 10m/s^2 is the gravity acceleration.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( " This change of the potential energy is spent to increase the kinematic energy of the body \r\n" );
document.write( "\r\n" );
document.write( " from 0 to  . where v is the magnitude of the velocity at the end.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( " So, = mgh. It is nothing elese as the energy conservation law in this problem.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( " Canceling \"m\" in both sides, you get  = 2gh, or v =  .\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( " The last step is to substitute h = 5 m, g = 10 m/s^2 into this formula, and you get\r\n" );
document.write( "\r\n" );
document.write( " v =  =  = 10 m/s.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "ANSWER. The final speed (the magnitude of the velocity) is 10 m/s.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "(b) In this problem, the speed rise from 0 to 10 m/s uniformly with time.\r\n" );
document.write( "\r\n" );
document.write( " \r\n" );
document.write( " Hence, the average speed is the average between 0 and 10 m/s, which is 5 m/s.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( " It implies that the time taken to slide is the full distance of 10 meters divided by the average speed of 5 m/s\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( " time taken to slide =  = 2 seconds.\r\n" );
document.write( " \r
\n" );
document.write( "\n" );
document.write( "Solved. // Both questions are answered.\r
\n" );
document.write( "
\n" );
document.write( "
\n" );
document.write( "\n" );
document.write( " \n" );
document.write( " |