Find the work done by a force F = 6i − 8j + 9k that moves an object from the point (0, 10, 4) to the point (4, 16, 18) along a straight line. The distance is measured in meters and the force in newtons.

Respuesta :

Answer:

102 J

Explanation:

Work done by a force

= Force x displacement

In case of vector form of force and displacement , we take dot product of force and displacement to calculate work.

The vector form of line which joins the two given points is given by the equation

d = (4-0) i +(16 - 10)j +( 18 - 4 )k

= 4i +6j +14k

Work done = F . d

(6 i -8J+9k) . ( 4i +6 j + 14 k )

24-48 +126

= 102 J

Answer:

102 J

Explanation:

Given that, the force of a moving object is,

[tex]F = (6i-8j + 9k) N[/tex]

The object is moving from point (0,10,4) to the point (4,16,18).

Now we can calculate the displacement by the formula,

[tex]dr=(x_{2}- x_{2})i+(y_{2}- y_{2})j+(z_{2}- z_{2})k[/tex]

Put all the values from the given values.

[tex]dr=(4- 0)i+(16-10)j+(18-4)k\\dr=(4i+6j+14k) meters[/tex]

Now, the work done can be calculated as,

[tex]W=F.dr[/tex]

Therefore,

[tex]W=(6i-8j + 9k).(4i+6j+14k)\\W=102J[/tex]

Therefore, work done is 102 J

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