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RosanelladC1-Visitor
1-Visitor
April 21, 2013
Question

Work done by forces: problem with dot product

  • April 21, 2013
  • 4 replies
  • 1978 views

I'm preparing a worksheet that will help me to work out work done by forces for different situations. But for the life of me I cannot get the dot product to display properly, hence set up the energy conservation equation.

I've enclosed my worksheet with my comments are in red.

By the way, why everything becomes bolded even if only one character/word is bolded in a non-text region?

4 replies

Werner_E
Werner_E25-Diamond I
25-Diamond I
April 21, 2013

Look if the attach helps

RosanelladC1-VisitorAuthor
1-Visitor
April 21, 2013

Thank you Werner.

And basically I simply use the '*' sign for dot product and Mathcad will know the difference?!?

But I don't understand why the colour or format changes even if only one character is selected (in this case I've selected v, as per your instructions; still, everything changes into the colour I've selected--the same happens if I only select bold, for instance).

Werner_E
Werner_E25-Diamond I
25-Diamond I
April 22, 2013

And basically I simply use the '*' sign for dot product and Mathcad will know the difference?!?

Yes, if both operands a vectors, Mathcad will interpret the multiplication sign as scalar product.

Keep in mind that there is a difference between v*v and v^2. The latter is not defined for vectors and so Mathcad does an implicit vectorization here, the outcome being a vector, not a scalar.

And basically I simply use the '*' sign for dot product and Mathcad will know the difference?!?

But I don't understand why the colour or format changes even if only one character is selected (in this case I've selected v, as per your instructions; still, everything changes into the colour I've selected--the same happens if I only select bold, for instance).

You cannot change single letters in a Mathcad's math expression as you can in a text region. Mathcad offers a range of styles (variable. constants, function, and some user defineables) to do what you want. If you select a variable and change it to bold, Mathcad will change the style and all variables will get bold. Its similar ro style sheets in a word processor with the exception that with Math expressions you are forced to use them.

I have introduced a style "vector" which is bold, purple and somewhat larger than the rest. If you change on of the purple v to black, all will get black, as you don't change that specific letter but rather the style. Think this is implemented that way for consistancy sake.

If you implement your own styles they will be connected to the worksheet. To have them available for all you newly created worksheets you will have to edit the template file (usually normal.mct).

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