vi is going in the positive direction (up). (That's my choice). a (acceleration) is going in the minus direction (down). The directions could be reversed.
Givens
vi = 160 ft/s
vf = 0 (the rocket stops at the maximum height.)
a = - 9.81 m/s
t = ????
Remark
YOu have 4 parameters between the givens and what you want to solve. Only 1 equation will relate those 4. Always always list your givens with these problems so you can pick the right equation.
Equation
a = (vf - vi)/t
Solve
- 32 = (0 - 160)/t Multiply both sides by t
-32 * t = - 160 Divide by -32
t = - 160/-32
t = 5
You will also need to solve for the height to answer part B
t = 5
vi = 160 m/s
a = - 32
d = ???
d = vi*t + 1/2 a t^2
d = 160*5 + 1/2 * - 32 * 5^2
d = 800 - 400
d = 400 feet
Part B
You are at the maximum height. vi is 0 this time because you are starting to descend.
vi = 0
a = 32 m/s^2
d = 400 feet
t = ??
formula
d = vi*t + 1/2 a t^2
400 = 0 + 1/2 * 32 * t^2
400 = 16 * t^2
400/16 = t^2
t^2 = 25
t = 5 sec
The free fall takes the same amount of time to come down as it did to go up. Sort of an amazing result.
Answer:

Step-by-step explanation:
3p + 4r = q
3p = q - 4r

The area is 4 square meters, because 2x2 would be 4
Answer:
The correct number of basic operations that exist in mathematics is four (addition, subtraction, multiplication and division) because the definition of an operation is the carrying out of a task by the application of principles and these four operation are arithmetic operations that have precedence rules or order of operations, such that we must first multiply or divide before adding or subtracting
Division is different from simply multiplying by a fraction because in Euclidean division, the result is a quotient and a remainder, which shows that division can yield more than one result while multiplication yields a single result
For subtraction and addition, one of the differences is that subtraction cannot be simply commuted
a - b = -(b - a)
Subtraction is non-associative;
a - b - c when arranged as (a - b) - c and a - (b - c), can yield different results depending on operation order which is unlike addition
Therefore, the four basic operations in mathematics are addition, subtraction, multiplication and division
Step-by-step explanation: