cq_1_242

#$&*

PHY 241

Your 'cq_1_24.2' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.

** CQ_1_24.2_labelMessages **

A steel ball of mass 60 grams, moving at 80 cm / sec, collides with a stationary marble of mass 20 grams. As a result of the collision the steel ball slows to 50 cm / sec and the marble speeds up to 70 cm / sec.

• Is the total momentum of the system after collision the same as the total momentum before?

answer/question/discussion: ->->->->->->->->->->->-> :

m1v1+m2v2=m1v’1+m2v’2

60g*80 cm/s +20g*0=60g*50 cm/s +20g*70 cm/s

60g*80 cm/s +20g*0=60g*50 cm/s +20g*70 cm/s

4800g cm/s=4400g cm/s

#$&*

• What would the marble velocity have to be in order to exactly conserve momentum, assuming the steel ball's velocities to be accurate?

answer/question/discussion: ->->->->->->->->->->->-> :

60g*80 cm/s +20g*0=60g*50 cm/s +20g*v’2

4800g cm/s=3000 g cm/s+20gv’2

V’2=90m/s

#$&*

** **

5min

** **

&#Good responses. Let me know if you have questions. &#