00:01
Hello students.
00:03
In this question we have given that a skateboarder of mass 47 kg.
00:09
He is moving on a ramp which is at height of 44 meter with velocity 6 .4 meter per second.
00:19
We have to write the expression for work done by the fractional force between ramp and skateboarder.
00:30
So this will be equal to work done by frictional force will be equal to the change in energy.
00:41
Change in energy that is the kinetic energy of skateboarder that will be half mv square minus his potential energy that is m g h.
00:57
This will give the work done by the frictional force.
01:04
Now for the second part we have given that theta is 30 degree which is given in the second figure.
01:19
The ramp is inclined at 30 degree and the height is same or let's say height is edge and distance d will be covered by the skateboard.
01:31
So here the expression for energy conservation will be half m v .i squared that is phase kinetic energy plus the work done by frictional force.
01:54
This will be multiplied by distance will be equal to phase potential energy.
02:01
Now we can write h as, we can write d s from this figure.
02:18
As you can see it clearly and this will be equal to ngh.
02:24
Now we have given that theta is 30 degree...