Chanllenge Problem:A Passing Fancy
Introduction:
Let us say that you're driving down the highway at a comfortable 55mph when suddenly you look in your rearview mirror and notice a car coming up on your really fast.You begin to wonder to yourself,”How fast is that guy going?”Here is an easy way to find out.At the instant your two windshields are aligned,start counting.When you reach a count of ten,keep counting,but note the location of the front wheels of the other car using some sort of natural marker-a lane stripe,lamp post,crack in the concrete,whatever.When your front wheels reach the same spot,stop counting.To find the speed of the other car,simply divide the number you counted to by ten and then multiply the result by your speed.For example.if you counted to thirteen by the time your car reached the designated marker,the speed of the other car would be calculated in the following way:13/10x55mph=72mph.
Problem:
In the space below,use one or more of the kinematic equations introduced this chapter to create a mathematical argument that shows that this method for calculating the speed of another motorist is valid.In other words,derive(or develop)the formula Vother=(tyou/tother) X Vyou beginning with one or more of the equations that describe uniform,one-dimensional motion.Be sure to write down any assumptions that you make during your derivation.
别用英文给我讲 我都不行了~