SBEC Chemistry and Physics

7 Responses to “Physics 1-8-09 Collisions Problems Review 2”

1.   Meredith Says:
   January 8th, 2009 at 11:26 PM

   Did anyone get number 36 on the homework last night? It is probably an easy one but I just couldn’t figure it out. Its the one when there is a moving object that has a kinetic energy of 150 J and a momentum with a magnitude of 30.0 kg-m/s. And you had to determine the mass and speed of the object.

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2.   Michael Says:
   January 9th, 2009 at 12:33 AM

   Meredith: Solve the formulas KE = (1/2)mv² and p = mv for m. Since you’ll have two equivalents for m after that, set those two formulas equal to each other and solve for v. Once you have the velocity, it is easy to find the mass.

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3.   Micah McCarter Says:
   January 9th, 2009 at 11:53 AM

   I’m wondering why number 39 is not considered a perfectly inelastic problem, the dart hits the wood block and they continue on as one object, in class we worked it as an inelastic problem.

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4.   kevin Says:
   January 9th, 2009 at 10:24 PM

   Micah : maybe it is because the whole thing remain at rest only the middle of it came off with the dart so it considered it as inelastic not perfectly inelastic

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5.   Jessi Howard Says:
   January 9th, 2009 at 11:00 PM

   Does our light bulb drop project have to work because we decreased the force by increasing the time of impact or if we think of another way to decrease the force will that be ok?

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6.   Ms. Skinner Says:
   January 9th, 2009 at 11:16 PM

   Jessi: Don’t forget this project is all about applying what you know about impulse and change in momentum to design a package. Check out the project sheet – “We are not testing the effects of air resistance here, but the effects of good packaging as it relates to changes in momentum. Therefore, you may not use designs that are meant to increase air resistance such as parachutes, gliders, etc.” That’s not what you were thinking of, was it?

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7.   Richard Says:
   January 10th, 2009 at 7:22 PM

   What if our packaging does increase the time of impact, but it also sort of increases air resistance unintentionally?

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