课程名称︰普通物理学乙 课程性质︰牙医系大二必修 课程教师︰董成渊 开课学院：理学院 开课系所︰物理系 考试日期（年月日） 2008/11/26 考试时限（分钟）：两堂课 是否需发放奖励金：yes （如未明确表示，则不予发放） 试题 : 1.Independent measurements (with errors) were made on the length(l±△l) and radius (r±△r) of a cylinder. Please derive the formula for the volume V±△V. Derive the errors for the volume measurements assuming that the errors for length and radios are independent. (14%) 2.A small block, mass m, slides down a frictionless surface through height h and then stricks to a uniform rod of mass M and length l. The rod pivots about point O through angle θ before momentarily stopping. Find θ. 3.A funny car accelerates from rest through a measured track distance in time T with the engine operating at a constant power P. If the track crew can increase the engine power by a differential amount dP, what is the change in the time required for the run? (14%) 4.Two speakers aeparated by distance d1=2.00m are in phase. Assume the amplitudes of the sound waves from the speakers are approximately the same at the listener's ear at distance d2=3.75m directly in front of one speakers. Consider the full audible range for normal hearing, 20Hz to 20kHz. (a)What is the lowest frequency f(min,1) that gives minimum signal (destructive interference) at the listener's ear? By what number must f(min,1) be multiplied to get (b)the second lowest frequency f(min,2) that gives minimum signal? (c)What is the lowest frequency f(max,1) that gives maximum signal (constructive interfeerence) at the listener's ear? By what number must f(max,1) be multiplied to get (d)the second lowest frequency f(max,2) that gives maximum signal? (12%) 5.A baseball is hit at a height h=1.00m and then caught at the same height. It travels alongside a wall, moving up past the top of the wall 1.00s after it is hit and then down past the top of the wall 4.00s later, at distance D=50.0m farther along the wall. (a)What horizontal distance is traveled by the ball from hit to catch? What are the (b)magnitude and (c)angle (relative to the horiaontal) of the ball's velocity just after being hit? (d)How high is the wall? (16%) ∣← D →∣ █████████ █████████h=1.00m 6.A uniform thin rod of length L, mass m, is lying on the usual smooth horizontal table. A horizontal impulse, P, is suddenly applied perpendicular to the rod at one end. (a)How far does the rod travel during the time it takes to make one complete revolution? (b)What are the translational, rotational, and total kinetic energies of the rod after the impulse? (15%) 7.A solid cylinder rolls, mass m, from the rest on an incline angled at θ. (a)What is the acceleration at the center of mass? (b)Please proof the cylinder will slip when the coefficient of static friction μs＜ (tanθ/3). (15%) ------- 附可能用到的值 ----------- The following formulas may be useful: (1)The rotational inertia of thin rod, length L, about axis through center perpendicular to length is (1/12)ML^2 (2)The rotational inertia of solid cylinder, tadius R, length L, abort central is (1/2)MR^2. (3)Sounds velocity 343m/s 题目卷不收回 --

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