精華區beta NTU-Exam 關於我們 聯絡資訊
課程名稱︰動力學 課程性質︰系必修 課程教師︰蕭浩明 開課學院:工學院 開課系所︰機械系 考試日期(年月日)︰2010-04-13 考試時限(分鐘):120分鐘 是否需發放獎勵金:是,謝謝 (如未明確表示,則不予發放) 試題 : 1. The pin follows the path described by the equation r = a + bcosθ. At the instant θ =30 度(我不會打那個上標的小圓) ,the angular velocity θ' and angular acceleration θ"are 0.7 rad/s and 0.5 rad/s^2. Determine the magnitudes of the pin's velocity and acceleration at this instant. Given a=0.2 m and b=0.15 m. (15%) 2. A single wire ACB of length 2m passes through a ring at C that is attached to a sphere which revolves at a constant speed v in the A ﹨ horizontal circle shown (以O為圓心,OC為半徑之圓). Knowing ﹨ that∠OBC =60度 and ∠ABC =30度 and the tension is the same ﹨ in both portions of the wire,determine the speed v. (15%) ﹨ B ﹨ ╲ ﹨ ╲ ﹨ ╲ ﹨ ╲﹨ O‧ ● C 3. The boy of mass 40kg is sliding down the spiral slide at a constant speed such that his position, measured from the top of the chute, has components r=1.5m θ=0.7t and z= -0.5t. Determine the components of force Fr,Fθand Fz which the slide exerts on him at the instant t=2sec. Neglect the size of the boy. (螺旋狀的滑梯,半徑固定,螺距固定) (15%) 4. | |-------5m-----------| A basketball player shoots when she is 5m →| |←d from the backboard. Knowing that the ball _|____ has an initial velocity v0 at an angle of | | ﹨ 30度 with the horizontal, determine the | 30度↖ value of v0 when d is equal to 430mm. | 3.048m _____● | ﹨ | 2m | _∕_________________∕_ (10%) 5. Plane A is flying along a straight-line path, while plane B is flying along a circular path ↑ 700 km/hr ↑600 km/hr having a radius of curvature of r=400km. Determine the velocity and acceleration of B ▲ A ▲ B as measured by the pilot of A. (飛機B作圓周運動,圖我畫不出來) ↑50 km/hr^2 ↓100 km/hr^2 | | | | |------4km-------| | | (15%) | | 6. The small object is placed on the inner surface of the conical dish at the radius shown. If the A | 0.2m | / coefficient of static friction between the object | / and the conical surface is 0.30, for what range of | m◇/ angular velocities ω about the vertical axis AB will | / the block remain on the dish without slipping? | / Assume that speed changes are made slowly so that any | / angular acceleration may be neglected. B |∠ 30 度 (15%) 7. A A 1-kg collar C slides without friction along the rod OA ╱ and is attached to rod BC by a frictionless pin. The rods ╱ rotate in the horizontal plane(ABCO皆在一水平面上). At C ╱ the instant shown BC is rotating counterclockwise and the ◆ speed of C is 1m/s, increasing at a rate of 1.3m/s. ╱∕ Determine at this instant the tension in rod BC. ╱ ∕ Given sin 23.8度 = 0.40 and cos 23.8度 =0.92. O╱ ∕ 附註: ∕ OB=0.3m, BC=0.6m ∕ 角OBC=30度 ∕ B∕ -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 140.112.199.210
shrek0665 :第一次畫圖... 04/17 16:18