7.5 Example 5

In the system shown in the image, if the stress in the string A is 2 Newtons. Which is the stress in the string B? Which is the mass block?

Solution with FisicaLab

Borramos el contenido de la Pizarra, seleccionamos el sistema de unidades SI, y agregamos un elemento Sistema de referencia fijo, un elemento Punto, y un elemento Bloque. Al elemento Punto le agregamos tres elementos Fuerza, y al elemento Bloque solamente uno, para formar dos diagramas de cuerpo libre, tal y como se muestra en la siguiente imagen:

The element Stationary reference system write to default the gravity value. To the element Point the name is irrelevant. To the oblique force, that correspond to the stress in the string A, write:

f

2

ang

35

To the oblique force that correspond to the stress in the string B, write:

f

B

ang

22

Because the magnitude of the force is an unknown data. To the vertical force, applied to the Point, that correspond to the stress in the string that support the block, write:

f

t

Is an unknown data. To the element Block, write:

m

m

Because its mass is an unknown data. To the vertical force, applied to the block, write the same unknown data assigned to the vertical force applied to the Point (is the same string):

f

t

Now click in the icon Solve to get the answer.

t = 1.809 N ;  B = 1.767 N ;  m = 0.184 kg ;
Status = success.