Angular Acceleration - Introductory Physics - Solved Paper, Exams of Physics

Download Angular Acceleration - Introductory Physics - Solved Paper and more Exams Physics in PDF only on Docsity! Physics 8A Spring 2008 Final Exam 1. (1 pt) Write your D/L section number on your exam. 2. (14 pts) A car is traveling along a road at 15.0 m/s when it passes a second car that is at rest. At a point in time when the first car is 20.0 m in front of the second, the driver of the second car puts his foot on the accelerator, causing his car to speed up at a rate of 1.50 m/s. (2) How long will it take him to pass the first car? (b) How fast will he be traveling as he passes the first car? (c) How far will he have traveled up to that point? 3. (40 pts) A block of mass 3.0 kg is being pushed against a wall with a horizontal force of 170 N. The coefficient of static friction between the wall and the block is 0.25; the kinetic friction coefficient is 0.10. (a) Will the block slide l7oN down the wall? (b) What minimum force must be exerted upward on the block to get it started moving up the wall? (c) If this force is continually applied, what will be the acceleration of the block once it starts moving up the wall? 4. (10 pts) A uniform rod is free to pivot about one end in a vertical plane. Initially, it is oriented vertically above the pivot point. It then starts to fall to one side. (a) When the rod reaches the horizontal position, what is its angular speed? (b) What is its angular ed) acceleration when it’s in the horizontal position? Note: The moment of inertia of a uniform rod is (1/12)ML? about the midpoint of the rod. enctie Lenel 5. (15 pts) A water tank is open at the top. The water surface is 35.0 m above the ground. A very narrow hose is attached to the side of the tank, 20.0 m above the ground, The hose runs all the way to the ground. However, the hose gets narrower as you go down, so that its diameter is one-half as large at the bottom as at the point where it’s joined to the tank. Water flows out of the tank through the hose, and exits into the open air at the ground. (a) Find the speed with which the water flows out of the hose at the ground. (b) Find the speed and pressure of the water as it’s flowing through the top of the hose (i.e., 20.0 m above the ground). 6. (10 pts) A 5.0 kg block is attached to a horizontal spring. At x = 1.50 m, the block is at maximum displacement, and has an acceleration of magnitude 6.0 m/s’. (a) Find the spring constant. (b) At = 0, the block is at x = 0.70 m, and is moving in the +x direction. Find the equation of motion x(#). (c) Find the velocity of the block at r= 0. 7. (10 pts) A wire of mass 10.0 g and length 2.0 m is vibrating in the fourth harmonic. The frequency of vibration is 500 Hz. (a) What is the tension in the string? (b) Suppose a pipe that is open at one end is placed next to the wire, and is made to vibrate in the fundamental. What possible lengths could you make the pipe so that, when combined with the sound created by the vibrating wire, it produces a beat frequency of 20 Hz? 8. (15 pts) A gas first goes through the process in the p b PV diagram from a to 6, which is a straight line in the diagram. It is then cooled at constant volume to point c. Finally, it is adiabatically compressed back a to point a. The pressure and volume at point a are 1.0 atm and 2.0 m’, and the pressure and volume at point 6 are 1.5 atm and 4.0 m’. (a) Find the pressure at point c. (b) Find the work done by the Cc gas and heat absorbed in the process from a to b. Note: 1 atm = 1.01 x 10° Pa. 9. (15 pts) A total of 5.0 g of water vapor at 100.0° C condenses onto a copper pipe that was initially at 0.0° C. The water that has been formed then comes into thermal equilibrium with the copper at a temperature of 10.0° C. (a) Find the tnass of the copper. (b) Find the total entropy change for the entire process. Note: The specific heat of copper is 387 J/kg-K; the specific heat of water is 4186 J/ke’K; the latent heat of vaporization of water is 2.256 x 10° J/kg; and 0° C corresponds to 273 K. Dron # mbt 2 u + domes mde) >tmit 3 ive Td meet! 39 w L Put = m5 (4) Coe t Tas tmein v Linck = bm 7S gmt “x x > 35 Ss. Cal {4 Leb ciy t rete Ae Wake par Faey pu bre ey t LAO A oF ye the hore ew h PR Le bute of +h, Lous, Tt. 2 Frey's Oy, Bik putes Psy, Vat © *pgh = Ya Fpvyiro Mi Mish = LOGE RT Som) ° 26.2 “Lp Vie A; Vy O> i. rd, = Vo: da, 2 . z Ar ea GY 2 a = 626.) ad > Ese ry, Pe teyleasy, R+dpMer 05% (tebe yoo at ty, of hore) Jorero® Pa & O + Cleon ey i4 EOS © on) 2 P + 4 (res elm ME OS el +O P72 7.2710" Pe Beg. ery Amen 7 WA C take On., te be mr agited. af treelees tie) a, A tan = ra Ko Amey rt) A ka memes 2 CS Oksh 6.0 ry A L.San 20.0 Mm Ors Fe -k x= ma, KA? me mex ket 1 Aime “— 7 LO Many (1 £OV= Aes lata gy OI m= LSOm cor ¥, Cos fo 7 O467 Po > 2 /.OF rock VG) 2 -wAsnlut+ 7%) Vi) -WwArud, Smu Vo} PO rede, fe SL ~10F rag Al so, ue fE 20.8 Mm = 1.0 ref, Cee) xO) ~ OF, Sori Co.) 62.0 reyes —1 69 rad] (e\ vtel~ “WAsIn?¢, += (1 eth Senta C~(04 ret} ~ 2.66 “f,