Relative vectors - how do you determine?

In summary, the conversation discusses a problem with coming up with relevant equations for questions and asks for tips. An example is provided where a passenger is walking on a bus traveling at a certain velocity, and the question asks for the passenger's velocity relative to two people walking in opposite directions on the sidewalk. The attempted solution involves assigning variables and using the formula Vpg = Vpb + Vbg, which is deemed correct by other users.
  • #1
Trooper100
15
0
1. The problem statement

I find it sometimes difficult to come up with the equation relevant to the question. If anyone has any tips, your help is appreciated.

2. Relevant example

For example:

A passenger climbs aboard a northbound bus and walks toward the back at a rate of 1.8m/s. The bus starts off up the street at 9.2m/s. What velocity will the passenger appear to be walking relative to:

A) a person who is walking 2.1 m/s south along the sidewalk
B) a person who is walking 2.1 m/s north along the sidewalk

The Attempt at a Solution



Let p = passenger in the bus
b = Bus
g = guy who is walking

My attempt: a) Vpg = Vpb + Vbg is this correct? why or why not? thanks.
 
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  • #2
Hi Trooper100! :smile:

(try using the X2 tag just above the Reply box :wink:)
Trooper100 said:
Let p = passenger in the bus
b = Bus
g = guy who is walking

My attempt: a) Vpg = Vpb + Vbg is this correct? why or why not? thanks.

Yes, that's correct, because you've put the letters in the right order … pg = pb + bg. :smile:

(For example , if you wanted to know Vpb,

you would write Vpb = Vpg + Vgb = Vpg - Vbg :wink:)
 

1. What is a relative vector?

A relative vector is a mathematical concept used to describe the direction and magnitude of a physical quantity in relation to another vector. It is defined by its direction and magnitude, and is typically represented by an arrow.

2. How do you determine the relative vector between two points?

To determine the relative vector between two points, you must first identify the origin and destination points. Then, you can calculate the difference between the coordinates of the two points to determine the direction and magnitude of the vector.

3. What is the difference between a relative vector and an absolute vector?

The main difference between a relative vector and an absolute vector is that a relative vector is described in relation to another vector, while an absolute vector is described independently of any other vector. Absolute vectors have fixed directions and magnitudes, while relative vectors can vary depending on the reference vector.

4. How do you use relative vectors in physics?

Relative vectors are used extensively in physics to describe the direction and magnitude of physical quantities, such as velocity, acceleration, and force. They are particularly useful in analyzing motion and calculating the net effect of multiple forces acting on an object.

5. Can relative vectors be negative?

Yes, relative vectors can be negative. The sign of a relative vector indicates the direction of the vector in relation to the reference vector. If the direction of the relative vector is opposite to the reference vector, it will have a negative sign.

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