00:01
One of them says that two people try to move a cajahed a material on a soil of a madeira.
00:07
One, a push the caja with 30 .1 newton's in direction positive.
00:15
So, we'll name this, the force 1 in this direction, the magnitude of the force 1 is equal to 30 .1 newtons.
00:34
While the other person hal a la caja with a force that we're going to call the force f2 and its magnitude is equal to 29 .2 newtons and has an angle of 15 .7 grados we'll let's this angle a lot it would be 15 7 degrees with respect to the horizontal.
01:19
This is this angle here.
01:24
And now we need to calculate the acceleration of the case if this is move horizontally.
01:30
The mass of the mass of the cajah is also to 13 .5 kilograms.
01:40
And we need a response between six figures and the coefficients of friction are done.
01:47
The coefficient of friction static is equal to 0 .5 and the coefficient of fription synethical is equal to 0 .3.
02:00
What we're going to do in this type of exercises is, first, to have all the forces that are applied to this body.
02:12
We have the two forces external.
02:15
Now, we have the forces normal, that is always perpendicular to the surface the peson of this mass that is the mass that's the acceleration of gravity and as we're friction, there's a force that that's upon the movement to the left.
02:41
So what we have to do now is to apply the second law of newton.
02:45
First, for the forces in the direction x.
02:51
So we just that for the right is positive.
02:58
So we have the force f1 plus the force f2, but this is the component x of this force.
03:10
So we have to multiply by the coseno of the angle that has given tita.
03:16
And this is the force of friction...