2.23 (Physics:
acceleration) Average acceleration is defined as the change of velocity divided
by the time taken to make the change, as shown in 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 in meters/second, and the time span t in seconds, and
displays the average acceleration.
Code :
File name-Acceleration.java
import java.util.*;
import javax.swing.*;
public class Acceleration {
public static void main (String arg[]){
Scanner input =new Scanner (System.in);
double value0, value1, t, avg;
System.out.print("Enter value for
v0: = ");
value0= input.nextDouble();
System.out.print("Enter value for
v1: = ");
value1= input.nextDouble();
System.out.print("Enter value for
t: = ");
t= input.nextDouble();
avg = (value1-value0)/t;
System.out.print("The average
acceleration is : = " + avg);
}
}
2.24 (Physics:
finding runway length) Given an airplane’s acceleration a and
take-off speed v, you can compute the minimum runway length needed for an
airplane to take off using the following formula: length = v2/2a
Write a
program that prompts the user to enter v in meters/second (m2/s)
and the acceleration a in meters/second squared and displays the minimum
runway length.
Code : File name-RunwayLength.java
import java.util.*;
import javax.swing.*;
public class RunwayLength {
public static void
main (String arg[]){
Scanner input =new
Scanner (System.in);
double
acceleration, speed, length;
System.out.print("Enter speed: =");
speed =
input.nextDouble();
System.out.print("Enter accelaration: =");
acceleration =
input.nextDouble();
length =
(Math.pow(speed, 2)/(2*acceleration));
System.out.print("The minimum runway length for this airplane is: =
"+length);
}
}
2.25* (Current
time) Listing 2.6, ShowCurrentTime.java, gives a program that
displays the current time in GMT. Revise the program so that it prompts the
user to enter the time zone offset to GMT and displays the time in the
specified time zone.
Code :
File name-CurrentTime.java
import java.util.*;
import javax.swing.*;
public class CurrentTime {
public static void main (String arg[]){
Scanner input =new Scanner (System.in);
System.out.print("The GMT time is: = ");
double gmt = input.nextDouble();
gmt = gmt*60;
long totalMilliseconds = System.currentTimeMillis();
long totalSeconds = totalMilliseconds/1000;
long currentSecond =(totalSeconds%60);
long totalMinutes = totalSeconds/60;
totalMinutes = (long)(totalMinutes+gmt);
long currentMinutes = (totalMinutes)%60;
long totalHours = (totalMinutes)/60;
long currentHours = totalHours%24;
System.out.println("Current time is " +currentHours +
":" +currentMinutes + ":" +currentSecond);
}
}
