2.9（物理：加速度）平均加速度定义为速度的变化量除以这个变化所用的时间，如下式所示： a = (v1 - v0) ÷ t
编写程序，提示用户输入以米/秒为单位的起始速度v0，以米/秒为单位的终止速度v1，以及以秒为单位的经过时间t，最后显示平均加速度。 下面是一个运行示例： Enter v0,v1,and t:5.5 50.9 4.5 The average acceleration is 10.0889
2.9(Physics: acceleration) Average acceleration is defined as the change of velocity divided by the time taken to make the change, as given by the following formula: a = (v1 - v0) ÷ t
Write a program that prompts the user to enter the starting velocity v0 in meters/ second, the ending velocity v1 in meters/second, and the time span t in seconds, then displays the average acceleration. Here is a sample run: Enter v0,v1,and t:5.5 50.9 4.5 The average acceleration is 10.0889
参考代码：
package chapter02; import java.util.Scanner; public class Code_09 { public static void main(String[] args) { double AverAcceleration,V0,V1,T; System.out.print("Enter v0, v1, and t : "); Scanner SpeedTimeInput = new Scanner(System.in); V0 = SpeedTimeInput.nextDouble(); V1 = SpeedTimeInput.nextDouble(); T = SpeedTimeInput.nextDouble(); AverAcceleration = (V1 - V0) / T; System.out.println("The average acceleration is " + AverAcceleration); } } 结果显示： Enter v0, v1, and t : 5.5 50.9 4.5 The average acceleration is 10.088888888888889 Process finished with exit code 0