2010_exam2_solutions2

2010_exam2_solutions2 - Solutions to 10-19 10. a) Use...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Solutions to 10-19 10. a) Use Newton’s 2 nd law of rotation for the pulley and the ordinary 2 nd law for the falling weight. Set the torque around the pulley = RT = I  and for weight find mg-T=ma. Finally realize that =a/R. Then 2 2 1 () 2 and - sosolvefor /2 6.7m/s 1 2 a RT I MR R mg T ma T TM a mg Ma ma m so a g mM    11. Balance the forces in the y direction: sin /sin 1600 Tm g g N 12. Set the potential energy at height 2R E equal to the sum of potential and kinetic at the earth’s surface: 2 1 0 22 EE GM m GM m PE PE KE mv RR      13. Use =I  or 11 12 2 2 12 2 2 R FR F II mR 14. Use energy conservation, set object’s KE+PE at the planet’s surface to zero, which is total energy of an object at rest at infinity. Get escape velocity 2 GM R where M is the planet’s mass and R it’s radius. So if the new planet has mass 2x that of earth, and half the radius, the factor GM/R increases by 4, so the square root goes up by 2.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 05/17/2011 for the course PHY 2053 taught by Professor Buchler during the Spring '06 term at University of Florida.

Page1 / 2

2010_exam2_solutions2 - Solutions to 10-19 10. a) Use...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online