Acceleration is:
a=g
Velocity is the integral of the above
v=gt+v0
And position is the integral of the above
h=gt^2/2+v0t+h0
You are given that v0=15ft/s and h0=0ft and let g≈-32 so
h(t)=-16t^2+15t
It will hit the ground when h(t)=0 so:
0=-16t^2+15t which is equal to
16t^2-15t=0 factor
t(16t-15)=0, since we are looking for the time other than zero...
t=15/16 of a second :)
So they obviously just rounded to one whole second. So C.) was the correct answer. (Although I would say they are all wrong because they didn't SAY to round the answer :P) Haha, not trying to confuse you, the answer is most likely C. because they had the correct equation.
Answer:
6 knots
Step-by-step explanation:
Let the speed be v knots
then time taken to cover 500 M = 500 / v hrs
fuel consumption /hr = 216 + 0.5v^3
let F be the fuel consumption for trip
= [500/v][216 + 0.5v^3]
= 500[216/v + 0.5v^2]
dF/dv = 500[ - 216/v^2 + v]
d^2F/d^2v = 500[432/v^3 + 1] , i.e. +ve
so setting dF/dv will give a minima
500[ -216/v^2 + v] = 0
or v = 216/v^2
or v^3 = 216
solving, we get v = [216]^(1/3) = 6 knots
Answer:
48
Step-by-step explanation:
8 divided by 2 = 4
4 times 12 = 48
Answer:34.4
Step-by-step explanation:
172.5-137.1=34.4
A lake near the Arctic Circle is covered by a 2-meter-thick sheet of ice during the cold winter months.
When spring arrives, the warm air gradually melts the ice, causing its thickness to decrease at a constant rate.
S(t) denote the ice sheet's thickness S ( measured in meters) as a function of time (measured in weeks).
Therefore the equation formed will be linear.
The equation will be of the form y = mx + b
Here S(t) = mt + b
Here m is the slope which is the rate at which ice is melting.
Putting t = 0
S(t) = 2
Putting t = 3,
S(t) = 1.25
Therefore, m*0 + b = 2 or, b = 2
and 3m + b = 1.25
or, 3m = 1.25 - 2 = -0.75
or, t = -0.25
Hence, function's formula = S(t) = -0.25*t + 2
i.e. S(t) = 2 - 0.25*t
