Chapter 2, Problem 1E

In physics, a common useful equation for finding the position s of a body in linear motion at a given time t, based on its initial position s₀, initial velocity v₀, and rate of acceleration a, is the following:

  $\text{s}=\text{s}0+\text{v}0\text{t}+12\text{at}2$

 Write code to declare variables for s₀, v₀, a, and t, and then write the code to compute s on the basis of these values.

Explanation of Solution

Code for declaring variables

• A declaration of a variable is where a program says that it needs a variable.
• The declaration gives a name and data type for the variable.
• A variable cannot be used in the program unless it has been declared.
• It also asks for a particular value that can be placed in the variable.
• Hence the code for declaring variables s₀,v₀,a and t is

 double s₀ = 12.0;

 double v₀ = 3.5;

 double a = 9.8;

 double t = 10.0;

• The code for computing s on the basis of these values is

 double s = s₀ + v₀ * t + 0.5 * a * t * t;

 System.out.println(s);