Question

somebody please please help: i'll give you a medal
Answer these questions about a light year.? Light travels 300,000,000m/sec, and one year has approximately 32,000,000 seconds. A light year is the distance light travels in one year. Based on this data:

a. state the speed in m/sec using scientific notation
b. state the speed in km/sec using scientific notation
c. state the number of seconds in one year using scientific notation
d. calculate the distance in meters of one light year
e. state this distance in centimeters

Answer 1

oK.. lets do this one by one

can u answer a) ?

Answer 2

well um, no i dont really know it

Answer 3

scientific notation is a way of writing big numbers with lots of zeros in an efficient way

so for example.. if you say length = 10,000 meters.. u can say it is 1 X 10^4 meters..
so we put it in 10 powers.. similarly can you put the speed of light in 10 powers?

Answer 4

would it be 3x10^8?

Answer 5

yes. correct.. don't forget the units though!

Answer 6

so its 3 X 10^8 meters/ sec

now second one b).. you have to put that in Km/sec..

Answer 7

units?
as in mph?

Answer 8

oh

Answer 9

ohh i have noooo idea how to do the second one

Answer 10

no its mentioned in your question .. "300,000000 m/sec"
so when you put that number in scientific notation, the units remain the same!

Answer 11

do you know how many meters is 1 km ?

Answer 12

oh, oh yeah :)

Answer 13

oh, um no

Answer 14

do u kno what KILO means?
u use it in kilo grams too..

Answer 15

hmm... um 100?

Answer 16

Nope.. don't you know how many grams is one kilo grams?

kilo = 1000

so if you say your weight is 50kilo grams that means you weight 50,000 grams :D..

so if you want to do it the other way around lets say

5 grams is how many kilo grams?

you do it as follows

1 kilo gram --------- 1000 grams
? --------- 5 grams?

cross multiply.. 5/1000 = 0.005 kilo grams! get it?

Answer 17

hmm.... umm...........ohhhhhhhhhhh!!!! yes i get it now!!! :D

Answer 18

ok.. so can you do question b) ? tell me how many Km/sec it is?

Answer 19

32?

Answer 20

or umm 3.2?

Answer 21

no no.. the same number 300,000,000 m/s convert that km/sec

Answer 22

oh, 300000?

Answer 23

or um something else??

Answer 24

correct.. now put that in scientific notation!

Answer 25

3x10^5?

Answer 26

yes.. with units.. don't forget to write units!!

Answer 27

oh yeah so 3x10^5 km/s?

Answer 28

correct!!

Answer 29

yes! thankyouthankyou

Answer 30

I leave c to you :P

Answer 31

now you have the skills to answer that!

Answer 32

oh well i um, dont know let me see

Answer 33

ll hit you.. if you say u dunno.. u know now!

Answer 34

oh, oh yeah i know now :)

Answer 35

32x10^6?????????

Answer 36

well.. u are almost right.. but the rule for scientific notation is

your number will always be less than 10.. everything else should be in 10 powers

for example 420000 = 4.2 X 10^ 5 and not 42 X 10^4
there are reasons for that.. lets not go into now :P
so .. what should be your answer for c?

Answer 37

and if i had 4230 i would write it as 4.23X 10^3 get it!?

Answer 38

um, yes... so its 3.2x10^6?

Answer 39

check ur ten power again :P

Answer 40

lol im sorry, im such a blonde i dont know whats the matter with the ten power haha

Answer 41

check how many decimals you gotta shift to get to 3.2
you had written 32 X 10^6
which is right, but its not the scientifc notation
so it should 3.2 X 10 power how much?!

Answer 42

hehe 5?

Answer 43

or 7??

Answer 44

when u shift decimal to the left ur ten power increases dude :P thats how you got to 10^6 in the first place.. now i ask you to shift ONE MORE .. so it would be?

Answer 45

7?

Answer 46

Right!

Answer 47

ooohhhh so its 3x10^7 km/s

Answer 48

NOooooooo
we are in c.. remember?!??!?

Answer 49

oh yeah yeah let me try to figure c out

Answer 50

wait isnt that the answer for c??

Answer 51

Noo.. cause u are now talking about TIME.. not the speed!!

Answer 52

oooooooooooooh

Answer 53

yea :P

Answer 54

so it would just be with "sec" at the end? or would it be m/sec?

Answer 55

i dunno you tell me.. but first get your number right

the question is convert "32000000 sec" into scientifc notation..

Answer 56

ooh okay, for sure this has to be the answer.... 3.2x10^7 sec

Answer 57

phew.. correct.. ahh.. :D..

Answer 58

yes!!!!!!!!!!!!!!!!! :D

Answer 59

now d.. try thinking hard and figuring out this one!

Answer 60

okay lemme see

Answer 61

so would meters equal 100?

Answer 62

no think harder.. try to feel the problem!

Answer 63

feel that problem..... hmm......

Answer 64

1000??

Answer 65

yea feel it..
they have told how much light travels in one second

and you have to calculate how much it travels in a year!!!

Answer 66

3.2e7 x 3e8??

Answer 67

yes yes!!.. now we are getting somewhere!!

Answer 68

now calculate that, remember give answer WITH UNITS!!

Answer 69

hmmm.......

Answer 70

ummm........

Answer 71

well it seems like........

Answer 72

hhm

Answer 73

:-/

Answer 74

i dont know what to do from there

Answer 75

just multiply them :O

Answer 76

ohh okay in that case it would be..... 3.2^15??

Answer 77

3.2 times 3 bro.. put ur head to it!

Answer 78

9.6??

Answer 79

yea so whats the answer?!

Answer 80

9.6^15??

Answer 81

units bro.. units?!

Answer 82

9.6^15 meters?

Answer 83

yes yes..

Answer 84

oh thats the right answer really?? i kinda guessed lol

Answer 85

:O.. i am so ashamed :/!

Answer 86

oh well it wasnt that much of a guess, i just put the first thing that popped into my head, well cause i, well, idk, lotsssssss of work i have to do

Answer 87

owkey.. last one!

Answer 88

lol okay lemme see

Answer 89

wait what number are we switching to centimeters?

Answer 90

the answer that you just obtained in meters.. to centi meters!

Answer 91

oooooh

Answer 92

0.096??

Answer 93

no try again!

Answer 94

0.96^15 cm??

Answer 95

is that it??

Answer 96

nope its not

1 meter = how many cm?

Answer 97

100

Answer 98

so now use that.. logic.. and get your answer