00:01
In this problem, we're going to talk about the work energy theory.
00:04
So what we need to remember is that the work done over an object is equal to the variation of energy of that object.
00:14
Also, that's the work can be written as the integral of the force over a certain, over the space.
00:28
Okay, so in our problem, we have a boy on a wheelchair.
00:33
The boy has a mass 47 kilograms and he is on the crest of a slope so this here is the slope the boy is on the top on his wheelchair sorry for my bed drawing and the height of the slope is 2 .6 meters while the length is 14 .12 .4 meters.
01:17
And the initial speed of the boy is 1 .4 meters per second.
01:23
His final speed is 6 .2 meters per second.
01:29
And all throughout his trajectory, the final speed at the bottom, i'm saying.
01:33
And the total force throughout his trajectory is 41 newton.
01:38
This is the friction force that acts on the boy, the total friction force...