Pinball with velocity vector (Vector calculus)

[Win_odd Dhamnekar]

Hi,

A pinball moving in a plane with velocity s bounces (in a purely elastic impact) from a baffle whose endpoints are p and q. What is the velocity vector after the bounce?

I don't understand how to answer this question? Any math help, hint or even correct answer will be accepted?

 

[Deleted member 4993]

Hi,

A pinball moving in a plane with velocity s bounces (in a purely elastic impact) from a baffle whose endpoints are p and q. What is the velocity vector after the bounce?

I don't understand how to answer this question? Any math help, hint or even correct answer will be accepted?

Draw a sketch of the problem and share.

Pure elastic impact will be a "reflection" .

 

[Win_odd Dhamnekar]

Draw a sketch of the problem and share.

Pure elastic impact will be a "reflection" .

The author has given the following answer to this question. Would you tell me how does the highlighted terms relate to velocity before and after the bounce?

 

[lev888]

The author has given the following answer to this question. Would you tell me how does the highlighted terms relate to velocity before and after the bounce?

View attachment 28014

Any thoughts regarding my reply on the other forum?

 

[Deleted member 4993]

The author has given the following answer to this question. Would you tell me how does the highlighted terms relate to velocity before and after the bounce?

View attachment 28014

You do understand that:

the "unit vectors" (u and v here) are defined by the position vectors q and p.​

​

the "dot product" of a "unit vector" with another "given" vector calculates the component of the given vector along the unit vector.​

​

So:

s \(\displaystyle \cdot \)u → component of s along u

 

[Win_odd Dhamnekar]

You do understand that:

the "unit vectors" (u and v here) are defined by the position vectors q and p.​

​

the "dot product" of a "unit vector" with another "given" vector calculates the component of the given vector along the unit vector.​

​

So:

s \(\displaystyle \cdot \)u → component of s along u

This question was solved. I got the correct answer.