final practice exam solutions

Physics for Scientists and Engineers (3rd Edition)

Info icon This preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
PHY131 Final Practice Exam Solutions 1) A mass M = 2.00 kg is attached to a hanging mass m = 0.50 kg by a massless cord which hangs over a massless and frictionless pulley. M m a) If there is no firction between the mass M and the horizontal surface, draw free body diagrams for the masses. Mg mg T T N b) Using the free body diagrams, find the tension in the rope. Newton’s second law: g m m m a a ) m M ( mg ma T mg and Ma T + = + = = = N 92 . 3 g M m mM Ma T = + = = c) Find the acceleration of the masses. 2 s m 96 . 1 5 g g 5 . 2 5 . 0 g m m m a : above see = = = + = d) If the masses move at constant speed, find the coefficient of friction between the mass M and the horizontal surface. 25 . 0 M m Mg N F mg T 0 a fr = = µ µ = µ = = = =
Image of page 1

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

View Full Document Right Arrow Icon
2) In the picture below, the system is in equlibrium. The boom has mass m = 12.0 kg and length l = 2.00 m. The point of attachment of the cord to the boom is at a distance 1.40 m (70 % of the length of the boom). The angle θ is 37 o . The suspended mass has m = 10.0 kg. Find the tension T in the horizontal cord. m T θ base point The system is in static equilibrium. Therefore, the sum of all torques about the base point (see drawing) has to be zero: N 168 12 . 1 mg 20 . 1 Mg 60 . 0 T 0 sin l mg sin 2 l Mg cos m 40 . 1 T = + = = θ × × θ × × θ × × = τ 3) A mass m = 0.500 kg oscillates on a frictionless horizontal surface with period T = 0.80 s. a) What is the spring constant k of the spring, which drives this motion?
Image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern