Answer:
a)
, b)
, c)
, d)
, e)
, f) 
Step-by-step explanation:
The velocity function can be derived by the differentiating the height function:

Velocities after 2 and 4 seconds are, respectively:
a) 
b) 
The maximum height is reached when velocity is zero. Then:

c) 
The maximum height is:
d) 
The time required to hit the ground is:

Roots of the second-order polynomial are:


Only the first root is physically reasonable.
e) 
The velocity when the projectile hits the ground is:
f) 
Answer:
Original sum of money = $2246.51
Step-by-step explanation:
Interest = $96.60
Interest is compounded 6 times in a year ; n = 6
time = 1 year ; Rate of interest (r) = 4.2%
Interest = Future Value - Principal Value ...........(1)
![\text{Future Value = }Principal\cdot (1+\frac{r}{100\times n})^{n\cdot t}\\\\\text{Substituting this value in equation (1) , We get }\\\\Interest=Principal\cdot (1+\frac{r}{100\times n})^{n\cdot t}-Principal\\\\\implies 96.60=Principal[\cdot (1+\frac{4.2}{100\times 6})^{6\cdot 1}-1]\\\\\implies Principal=\$2246.51](https://tex.z-dn.net/?f=%5Ctext%7BFuture%20Value%20%3D%20%7DPrincipal%5Ccdot%20%281%2B%5Cfrac%7Br%7D%7B100%5Ctimes%20n%7D%29%5E%7Bn%5Ccdot%20t%7D%5C%5C%5C%5C%5Ctext%7BSubstituting%20this%20value%20in%20equation%20%281%29%20%2C%20We%20get%20%7D%5C%5C%5C%5CInterest%3DPrincipal%5Ccdot%20%281%2B%5Cfrac%7Br%7D%7B100%5Ctimes%20n%7D%29%5E%7Bn%5Ccdot%20t%7D-Principal%5C%5C%5C%5C%5Cimplies%2096.60%3DPrincipal%5B%5Ccdot%20%281%2B%5Cfrac%7B4.2%7D%7B100%5Ctimes%206%7D%29%5E%7B6%5Ccdot%201%7D-1%5D%5C%5C%5C%5C%5Cimplies%20Principal%3D%5C%242246.51)
Hence, the original sum of money borrowed = $2246.51
Step-by-step explanation:

Given equaiton is in the form of ax^2 +bx+c=0
we apply quadratic formula to solve for x

a= 1 b = -12 and c= 59



Divide the 12 and square root terms by 2

so
and 
Answer: $2.75
Step-by-step explanation:
Zeke's helmet cost 3/5 x 28.75 = 17.25
Change = 20 - 17.25 = 2.75
Answer: high test-retest reliability
Step-by-step explanation: this is because the result of the survey was thesame with the previous result, despite the space of time between when the first survey was conducted and when the second survey was conducted. There was know observable difference in result and if conducted in the next 3 months again, it will give same result, this strongly indicate that the survey has high test-retest reliability.