Download 24497 BIL106E Introduction to Scientific and Engineering

24497 BIL106E Introduction to Scientific and Engineering Programming
2012-2013 Spring Semester Midterm Exam 1
05.04.2013
PROBLEM 1: (10p) Find the value of each of the following expressions
(a) 2/3/4
(b) 2/(3/4)
(c) 2/3/4.0
(d) 2/3.0/4
(e) 2**3**2
(f) 4**3/2
(g) 4**(3/2)
(h) 4**(3/2.0)
(i) 4.0**(3/2)
(j) "abcde"(3:5)//"-"// "99"
SOLUTION 1:
(a) 0
(b) division by zero
(c) 0.0
(d) 0.166666
(e) 512
(f) 32
(g) 4
(h) 8.0
(i) 4.0
(j) cde-99
PROBLEM 2: (10p) What will be the output of the following program?
program prn
integer :: i, j
do i = 5, 1, -1
print "(1x, 5i1)", (/(i-j+1, j=1, i)/)
end do
end program prn
SOLUTION 2:
◊54321
◊4321
◊321
◊21
◊1
PROBLEM 3: (10p) Consider the array numb = (/1, 2, 3, 4, 5, 6, 7, 8, 9, 0/). Print the array as
(a) a single row of numbers
(b) a single column of numbers
(c) two rows of five numbers
(d) five rows of two numbers
(e) a single row leaving one space between consecutive numbers
Your answers should be single print statements.
SOLUTION 3:
(a) print *, numb
(b) print "(i1)", numb
(c) print "(5(1x, i1))", numb
(d) print "(2(1x, i1))", numb
(e) print "(1x,10(i1, 1x))", numb
PROBLEM 4: (15p)Write a function the receives an integer number n as an argument and returns a
string value
"negative" – if n is a negative number
"zero"
– if n is equal to zero
"positive" – if n is a positive number.
SOLUTION 4:
function signum(n) result(ans)
integer, intent(in) :: n
character(len = 8) :: ans
select case(n)
case(:-1)
ans = "negative"
case(0)
ans = "zero"
case(1:)
ans = "positive"
end select
end function signum
PROBLEM 5: (15p) Write a subroutine that interchanges the first characters of two strings.
SOLUTION 5:
subroutine swapletter(a, b)
character(len = *), intent(inout) :: a, b
character(len = 1) :: temp
temp = a(1:1)
a(1:1)=b(1:1)
b(1:1)=temp
end subroutine swapletter
PROBLEM 6: (20p) Consider the figure below. The square OABC has
a sidelength of 1 cm. The coordinates of the point P are xP and yP,
respectively. Write a program that reads xP and yP and prints the output
message
y
C(0, 1)
B(1, 1)
P(xP, yP)
"inside"- when the point P is inside or on the edge of the square
"outside" - when the point P is outside the square.
x
O
A(1, 0)
SOLUTION 6:
program prob6
real :: xp, yp
print *, "Enter the x and y coordinates of the point P"
read *, xp, yp
if (xp<0.or.xp>1.or.yp<0.or.yp>1) then
print *, "outside"
else
print *, "inside"
end if
end program prob6
PROBLEM 7: (20p) The velocity of a particle P is defined by v P (t )  t 3  6t 2  11t  6 m / s .
Write a program that finds the instants in the interval t  0, 5s at which the velocity of the particle
is equal to zero. Do this by dividing the time interval into subintervals of 0.05 s and checking
whether the sign of the velocity function at an instant t i  t 0  i  t changes.
SOLUTION 7:
program prob7
integer :: i, n
real :: x1, x2, fx1, fx2
n = 5.0 / 0.05
do i = 0, n
x1 = i * 0.05
x2 = x1 + 0.05
fx1 = x1 ** 3 - 6.0 * x1 ** 2 + 11.0 * x1 - 6.0
fx2 = x2 ** 3 - 6.0 * x2 ** 2 + 11.0 * x2 - 6.0
if (fx1*fx2<0) then
print *, x1
end if
end do
end program prob7