Answer:

Step-by-step explanation:
We are given that
By ohm's law

R=389 ohm
I=0.03 A


We have to find rate of change of current I means 
Differentiate the equation w.r.t t

Substitute the values then we get





Hence, the current I is changing at the rate=-0.00016A/s
Answer with explanation:
Presume that, initial water level to be, 0 mm, at a time t=0.
And water level is rising at the rate of
.
After 6.2 years level of water will be =1.8 × 6.2
=11.16 mm
→Averge, that is increase in water level after 6.2 years is given by

→→Rate of Depreciating of water level is given by = Negative of Increase of water level=
If we divide the area we have to cover by the area of a piece, we will get the number of pieces needed:

Answer:
7 . 4 + 6 - 12 : 4 = 31
Step-by-step explanation:
* To solve this problem lets revise the order of operations in
mathematics
- The operations are:
# Addition
# Subtraction
# Multiplication
# Division
# Exponentiation
# Grouping ⇒ Parenthesis or brackets
- The order of these operations is:
# Parenthesis
# Exponents
# Multiplication and Division which comes first from left to right
# Addition and Subtraction which comes first from left to right
- There is a word made from the first letter of each operation
PEMDAS to remember the order of operations
* Lets solve the problem
∵ 7 . 4 + 6 - 12 : 4
∵ The (.) means multiply the numbers
∵ The symbol (:) means divided the numbers
∴ At first multiply 7 by 4 and divide 12 by 4
∴ (7 × 4) + 6 - (12 ÷ 4)
∴ 28 + 6 - 3
∵ Addition comes before subtraction from the left
∴ (28 + 6) - 3
∴ 34 - 3 = 31
∴ 7 . 4 + 6 - 12 : 4 = 31
I really do not know the answer to this question