Vectors - determining ##\angle abc##

Thread starter angela107
Start date Jun 4, 2020
Tags

Vectors

Click For Summary

The discussion centers on the calculation of vector ##\vec{BC}##, with a correction noted regarding the inclusion of a minus sign. It emphasizes the importance of using vector ##\vec{BA}## instead of ##\vec{AB}## for accurate results. The participants clarify their conventions for vector notation, highlighting the difference in definitions. The conversation underscores the significance of attention to detail in vector calculations. Accurate vector representation is crucial for determining angles in geometry.

Jun 4, 2020

angela107

Homework Statement: can someone see if my work is correct?

Relevant Equations: n/a

Physics news on Phys.org

Jun 4, 2020

member 587159

I think you made an error with calculating the vector ##\vec{BC}=[-4,0,0]##. I think you missed the minus sign here. You also want to consider ##\vec{BA}## instead of ##\vec{AB}##, so your solution checks out because two negatives cancel each other out.

Perhaps I'm misunderstanding your convention but I use ##\vec{AB}= \vec{B}- \vec{A}##.

Thread 'Distance between a Clock's hands when the distance is increasing most rapidly'

Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

View full post »