Answer:

Step-by-step explanation:
Given


Required:
Determine the time taken to return to the ground
From the equation given; height (h) is a function of time (t)
When the rocket returns to the ground level, h(t) = 0
Substitute 0 for h(t) in the given equation

becomes

Solve for t in the above equation

Factorize the above expression

Split the expression to 2

Solving the first expression

Divide both sides by -4



Solving the second expression

Add 30 to both sides


Divide both sides by 4



Hence, the values of t are:
and 
shows the time before the launching the rocket
while
shows the time after the rocket returns to the floor
Answer:
y here's how you count by 5 10 15 20 25 30 35
The reliability of a two-component product if the components are in parallel is 0.99.
In this question,
The probability of failure-free operation of a system with several parallel elements is always higher than that of the best element in the system. Reliability can be increased if the same function is done by two or more elements arranged in parallel.
A system contains two components that are arranged in parallel, they are 0.95 and 0.80.
Therefore the system reliability can be calculated as follows
⇒ 1 - ( 1 - 0.95 ) × ( 1 - 0.80 )
⇒ 1 - (0.05 × 0.20)
⇒ 1 - 0.01
⇒ 0.99
Hence we can conclude that the reliability of a two-component product if the components are in parallel is 0.99.
Learn more about reliability of components here
brainly.com/question/20314118
#SPJ4
Answer:
Option a) 50% of output expected to be less than or equal to the mean.
Step-by-step explanation:
We are given the following in the question:
The output of a process is stable and normally distributed.
Mean = 23.5
We have to find the percentage of output expected to be less than or equal to the mean.
Mean of a normal distribution.
- The mean of normal distribution divides the data into exactly two equal parts.
- 50% of data lies to the right of the mean.
- 50% of data lies to the right of the mean
Thus, by property of normal distribution 50% of output expected to be less than or equal to the mean.