Mechanics: Momentum and Collisions

Momentum and Collisions: Audio Guided Solution

Problem Set MC10, Question 4:

Every momentum unit needs a Silly Putty problem and here's ours:  
Two pieces of 'Silly Putty' are thrown in opposite directions toward one another (for some reason), collide head-on (miraculously), and stick together after the collision (as one would expect). If one glob has a mass of 10.4 g and is traveling with a pre-collision speed of 9.4 m/s. The other glob has a mass of 4.7 g and a pre-collision speed of 5.4 m/s. What is the post-collision speed two-glob combo?
 




 

Audio Guided Solution




Habits of an Effective Problem Solver

An effective problem solver by habit approaches a physics problem in a manner that reflects a collection of disciplined habits. An effective problem-solver...

  • ...reads the problem carefully and develops a mental picture of the physical situation. If needed, they sketch a simple diagram of the physical situation to help visualize it.
  • ...identifies the known and unknown quantities in an organized manner, often times recording them on the diagram itself. Then equate given values to the symbols used to represent the corresponding quantity (e.g., vo = 0 m/s; a = 4.2 m/s/s; vf = 22.9 m/s; d = ???.).
  • ...plots a strategy for solving for the unknown quantity; the strategy will typically center around the use of physics equations be heavily dependent upon an understanding of physics principles.
  • ...identifies the appropriate formula(s) to use, often times writing them down. Where needed, they perform the needed conversion of quantities into the proper unit.
  • ...performs substitutions and algebraic manipulations in order to solve for the unknown quantity.


 

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