精華區beta NTU-Exam 關於我們 聯絡資訊
課程名稱︰普通物理學甲 課程性質︰ 課程教師︰張顏暉 開課系所︰電機工程學系 考試時間︰11/08 星期二 早上10:30~中午12:30 試題 : 1.A free falling body of mass m is subjected to a friction force -bv. Find the terminal speed of this body.(5) 2.The force on a particle is F=Fo(X/Xo-1). Find the work done by the force in moving the particle from X=0 to X=2Xo.(5) 3.A hot air balloon of mass M is descending vertically with downward accerlation of magnitude a. How much mass(ballast)must be thrown out to give the balloon an upward accerlation of magnitude a? Assume that the upward force from the air(the lift) does not change because of the decrease in mass.(10) 4.A worker wishes to pile a cone of sand onto a circular area in his yard. The radius of the circle is R, and no sand is to spill onto the surrounding area. If μs is the static coefficient of friction between each layer of the sand along the slope and the sand beneath it, what is the greatest volume of the sand that can be stored in this manner?(The volume of the cone is Ah/3, where A is the base area and h is the cone's height) (10) 5.A stone with weight w is thrown vertically upward into the air from ground level with speed Vo. If a constant force f due to air drag acts on the stone throughout its flight.(a) What's the maximum height can be reached by the stone?(b) What's the speed of the stone when it reaches the ground? 6.A small ball of mass m is, with a slight seperation, aligned above a large ball of mass 1kg and the two are dropped simultaneously from height of h=2m (Assume the radius of each ball is negligible relative to h) (a)If the larger ball rebounds elastically from the floor and then the smaller ball rebounds from the largerball, what value of m results in the larger ball stoping when it reaches the ground?(10) 7.At t=0, particle A of mass 1 kg is located at (1,0) (in meter) with a velocity of 1 m/s in positive x-direction, and particle B of mass 1 kg is located at (1,0) with velocity 1 m/s in positive y direction. What is the velocity of the center of mass and total angular momemtum with respect to O of this two particles system? A force of 1Nt in the postive y-direction acts on particles for 1s. 10s after the force is removed, what is the velocity of the center of mass and total angular momemtum with respect to O of this two-particle system. 8.Calculate the rotational inertial of a thin rod of length L and mass M about an axis perpendicular to the rod, through the center of mass? Use parallel axis theorem to find the rotational inertial of the same rod about an axis passing through one end of the rod. This rod can pivot about a horizontal frictionless pin through one end. It is released from horizontal position, find the augular speed of the rod when it makes an angle Θ with the horizontal axis. Find also the force acting on the pivot. 9.A uniform solid disk of radius R and mass M is given an initial angular velocity ωo and the lowered on to a flat horizontal surface (Icm=1/2MR平方). The coefficient of kinetic friction between the surface and the cylinder is μk. Initially the disk slips as it moves along the surface, but after a time t0 pure rolling without slipping begins. (a) what is the value of t0? (b) What are the kinetic energies (transtional plus rotational) of the sphere at t=0 and t=t0? (c) What is the distance (S) traveled by the CM from t=0 to t=t0 and what is the angle (ΔΘ) rotated by a point P at the edge of the disk? (d) Show that the difference in the total kinetic energy at t=0 and t=t0 equal to the friction force times the difference between S and RΔΘ. (20) 10. Write down your opinion on this course. Does the professor explain things in a way you can understand? Do tou like his teaching style? What could be done to improve the teaching of this course. You need to write down more the 5 lines to get the extra 5 points.(5) -- So 發~~~~ So good!!!!!!!! -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 61.228.70.159