Vector Notation for Work: An Exploration of Force and Displacement

In summary, the conversation discusses a problem involving a given force in vector notation and the attempt to calculate the displacement using the given formula for work. However, the solution process does not work and it is found that the initial displacement has a missing k component. After further calculations and guidance, the correct displacement is determined to be 5i - 21j + 14k.
  • #1
warnexus
90
0

Homework Statement


workVectors.png



Homework Equations


Work = F* delta x


The Attempt at a Solution



My thought process since the force is given in vector notations multiply the pair of i components together same applies with j and k components. However this process actually strangely does not work. And I am baffled by why a k component missing for the initial displacement.
 
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  • #2
The k component happens to equal 0 at the initial position. So what?

Figure out the displacement: r2-r1
 
  • #3
after substraction I get 5 i - 21 j + 14k.

5i(67i) + 23j(-21j) + 55k(14k) = 335 - 483 + 770 = 622 J <- correct! =]

thanks for the guidance, Doc Al.
 

What is Vector Notation?

Vector notation is a mathematical representation of a vector, which is a quantity that has both magnitude (size) and direction. It is typically written as an arrow above the variable, such as →F to represent the vector force.

How is Work Calculated Using Vector Notation?

Work is calculated using the dot product of two vectors, which is the product of their magnitudes and the cosine of the angle between them. In vector notation, this can be represented as W = →F ⋅ →d, where →F is the force vector and →d is the displacement vector.

What is the Significance of Using Vector Notation in Work Calculations?

Vector notation allows for a more accurate calculation of work, as it takes into account both the magnitude and direction of the force and displacement. It also allows for the use of multiple forces and displacements in the same calculation, making it a more versatile and comprehensive method.

How is Work Expressed in Vector Notation?

In vector notation, work is expressed as a scalar quantity, meaning it has only magnitude and no direction. The unit of work is joules (J) in the SI system, and it is written as W = F ⋅ d ⋅ cos(θ), where F is the magnitude of the force, d is the magnitude of the displacement, and θ is the angle between the two vectors.

What are Some Common Applications of Vector Notation in Work Calculations?

Vector notation is used in various fields, such as physics, engineering, and mathematics, to calculate work in different scenarios. Some common applications include calculating the work done by a force on an object, the work done by a machine, and the work done in moving an object against a resisting force.

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