ShmoopTube
Where Monty Python meets your 10th grade teacher.
Search Thousands of Shmoop Videos
PSAT Videos 97 videos
PSAT 1.1 Math Diagnostic. If a rabbit consumes 3 meals a day, how many grams of food will a rabbit consume in 7 days?
PSAT 1.17 Math Diagnostic 180 Views
Share It!
Description:
PSAT 1.17 Math Diagnostic. Which of the following functions models the number of E. coli bacteria at time h?
More Video DetailsTranscript
- 00:00
Thank you We sneak And here's your shmoop du jour
- 00:05
brought to you by e coli Once you've gone e
- 00:08
coli you never go back here yet All right so
- 00:14
check out this info time sudden memory for people down
- 00:20
All right we get it Which of the following functions
Full Transcript
- 00:23
models the number of e coli bacteria at time age
- 00:27
where h represents the number of hours since the experiment's
- 00:30
started And here essential answers All right the functions of
- 00:35
ours All right well first of all it's fine If
- 00:37
you want to leave e coli bacteria on the lab
- 00:39
table But police be sure the labeling last thing you
- 00:42
ever want to have happen is for some unsuspecting fellow
- 00:45
scientist to see the dish and mistaken for his chobani
- 00:48
blended plum yogurt All right well he might be spending
- 00:51
the next three or four hours in the emergency shower
- 00:53
Okay so were given a pretty simple looking table and
- 00:57
we're supposed to use the shadow there to assemble a
- 00:59
written function that represents the number of e coli bacteria
- 01:02
in relation to age the number of hours Well let
- 01:06
zero hours there in just fifteen bacteria in a petri
- 01:09
dish with scientists started out with every hour after that
- 01:13
it looks like they doubled So should be just about
- 01:16
four five days until they take over The world ok
- 01:20
well maybe we're being alarmist here but until they start
- 01:22
growing limbs and learn how to open and close the
- 01:24
door when we should be fine the good news is
- 01:27
that because the reign of growth is constant from one
- 01:30
hour to the next way no that the relationship is
- 01:33
exponential which means we can use this formula Why equals
- 01:38
eight times the quantity One plus our to the x
- 01:41
power well has always pays the initial amount in this
- 01:44
case teen bacteria our is the growth rate one hour
- 01:49
and x is the number of compounding period since we're
- 01:53
using ours is our com pounding period let's replace the
- 01:56
acts within age unless your friends are something in spell
- 02:00
ours with an x in which case well you just
- 02:03
keep it as is we'll also want to replace the
- 02:05
why of the f of age to make it more
- 02:08
you know function and we're left with f of h
- 02:11
g wells fifteen times two to the h power which
- 02:14
is option c if you want to double check to
- 02:17
make sure we set this thing up right We can't
- 02:19
look in any number from the time And we should
- 02:21
get the corresponding data in the table For example we
- 02:24
could plug in three thousand four hundred twenty seven hours
- 02:26
but we really don't want to be here all day
- 02:28
so instead we'll plug in five to two The fifth
- 02:31
power is who four eight sixteen thirty two times fifteen
- 02:36
which is four hundred eighty century enough consulting our table
- 02:40
After five hours there should be four hundred eighty bacteria
- 02:42
in the petri dish Option c It is all right
- 02:45
We've had enough of incredible multiplying bacteria If we wanted
- 02:50
to see something multiplied this fast we watched that new 00:02:53.24 --> [endTime] show on tlc thirty seven isn't enough
Related Videos
PSAT 1.3 Math Narrative Walkthrough. How many full packages of secret ingredient does the company have to buy to make one 50-gallon batch?
PSAT 1.1 Reading Diagnostic. The main purpose of the first two paragraphs is to...what?
PSAT 2.2 Reading Diagnostic. What is the main rhetorical effect of this phrase in the second paragraph?
PSAT 1.3 Writing Diagnostic. To make the paragraph most logical, sentence 2 in the second paragraph should be placed...where?
PSAT 1.4 Writing Diagnostic. Which choice most effectively combines the two sentences in the underlined portion?