国际基础第一学期期末作业国际基础第一学期期末作业.docVIP

一、Linear motion 1 (直线运动1） 1. An object is travelling with a speed of 4.2m/s in an Easterly direction on a straight road ,It changes its speed to 8.60m/s in 4.00s,calculate the magnitude of its acceleration.(一个物体在4秒内速度有4.2米每秒变为8.60米每秒，求加速度） 2. An object starts from rest and accelerates at a uniform rate of 2.40m/s until it reaches a speed of 38.4m/s.(一个物体以2.40的加速度从0加速到38.4米每秒） (a) calculate the time required to reach 38.4m/s.（计算所用时间） (b) draw a velocity-time graph of the motion during the time interval.（画出速度随时间变化的图像） 二、Linear motion 2(直线运动2） 1、 For the graph shown below state the following(根据图形计算下题） （a）velocity at 0.0s、 30s and 60s （b）Acceleration at 0.0s 、30s and 60s 2、 The graph below represents the motion of a dog along a street Which runs from east to west(一只狗从东往西跑，运动图像如下） （a）the instantaneous velocity of the dog at time=9s(求在9秒的瞬时速度） （b) the acceleration of the dog at time=3.0 seconds(求在3秒的加速度） （c）the average velocity of the dog for the time interval t=7.0sto9.0s（求7秒到9秒的平均速度） （d） sketch a graph showing velocity against time for this motion from t=0.0s to t=11s (画出从0到11秒的速度时间图像） 三、Linear motion 3(直线运动3） 1. Calculate the speed of a stone 5.00 s after it is dropped (the value of its acceleration is g=9.80m/s2)(计算一块石头从高处落下5秒时的速度） 2.A balloon is 50.0m above the ground and is descending with a uniform speed of 0.500m/s.when a pebble is dropped from it(一个气球在离地50米处，其速度以0.500m/s递减，一块石头从其中落下） (a) how long does it take the balloon to reach the ground(多久气球落地） (b) how long does it take the pebble to reach the ground(石头多久落地） (c) Calculate the speed of the pebble as it reaches the ground(计算石头落地速度） 3.A car starts form rest and accelerates uniformly for 20.0s,it travels a distance of 22.1m in the ninth second of its motion(一辆汽车从静止开始匀加速运动20s，在第9秒内经过路程为22.1米，） (a) calculate its acceleration (计算加速度） (b) Calculate its displacement during the 20.0 (计算20秒内总路程） 4. A car starts form rest and accelerates uniformly，it speed after 6.00s is36.0 km/h (汽车