Python Functions

1) Write a function that calculates the volume of a sphere with radius r for only values > 0, return 0 otherwise . V=4/3  π r^3

2)  Write a function that finds you weight in stones using the formula.  mstone = mkgx2.2/14

3) Write a function that takes some monetary amount from the user in dollars, and then display exact changes for this amount using the minimum number of coins. For example, $0.97 shows 3 quarters, 2 dimes, and 2 pennies. 

Output: 

change_it(97) 



The change for 97 cents is: 

3 quarters 

2 dimes 

2 pennies

 Write an function to calculate both Ohm’s Law and Power transferred. The function takes i and r as inputs and prints the results (see output below). Calculate only if both i and r are > 0. 

FORMULA

  i is current, v is voltage, r is resistance, p is power

 p = i * v   # power = current * volatage

  v = i * r   # voltage = current * resistance

def ohms_law(i, r): 

    '''

      i is current

      r is resistance

    '''

    # check if both i and r are greater than 0

    # calculate v and p

    # PRINT v and p

omhs_law(5, 5)

v = 25 p = 125



omhs_law(-5, -5)

0