Answer:
# Program is written in python
# 22.1 Using the count method, find the number of occurrences of the character 's' in the string 'mississippi'.
# initializing string
Stringtocheck = "mississippi"
# using count() to get count of s
counter = Stringtocheck.count('s')
# printing result
print ("Count of s is : " + str(counter))
# 2.2 In the string 'mississippi', replace all occurrences of the substring 'iss' with 'ox
# Here, we'll make use of replace() method
# Prints the string by replacing iss by ox
print(Stringtocheck.replace("iss", "ox"))
#2.3 Find the index of the first occurrence of 'p' in 'mississippi'
# declare substring
substring = 'p'
# Find index
index = Stringtocheck.find(substring)
# Print index
print(index)
# End of program
Answer:
The principal stresses are σp1 = 27 ksi, σp2 = -37 ksi and the shear stress is zero
Explanation:
The expression for the maximum shear stress is given:

Where
σx = stress in vertical plane = 20 ksi
σy = stress in horizontal plane = -30 ksi
τM = 32 ksi
Replacing:

Solving for τxy:
τxy = ±19.98 ksi
The principal stress is:

Where
σp1 = 20 ksi
σp2 = -30 ksi
(equation 1)
equation 2
Solving both equations:
σp1 = 27 ksi
σp2 = -37 ksi
The shear stress on the vertical plane is zero
Given acceleration a = 5-3t, and its velocity is 7 at time t = 2, the value of s2 - s1 = 7
<h3>How to solve for the value of s2 - s1</h3>
We have
= 


v2 = 5x2 - 3x2 + c
= 10-6+c
= 4+c

S2 - S1

= 6 + 6+c - 2+3+c
12+c-5+c = 0
7 = c
Read more on acceleration here: brainly.com/question/605631
Answer:
A wheelbarrow, a bottle opener, and an oar are examples of second class levers