Question

A goose is flying south for the winter at a constant speed. Keep in mind that one mile is 1.61 km and one pound is 454 g. The goose has a mass of 23.9
lb
(pounds) and is flying at 8.00
miles/h
(miles per hour). What is the kinetic energy of the goose in joules?

Answer 1

I got 900026.8883 J

Answer 2

hm, probably not, that's a lot of energy for one bird

Answer 3

anyway, this is a very complicated conversion factor but

let's start w/ 8.0 mph

Answer 4

ok

Answer 5

1 mile = 1.61 km as indicated by the problem so let's put that where it belongs so the units can cancel out

Answer 6

okay so it would be 1.61/1mile

Answer 7

60 minutes in an hour, 60 seconds in a minute

so applying these conversion factors:

Answer 8

Where do you 1 hr/60 min and 1min/60s conversions come into play. Like why are those there?

Answer 9

I'm sorry Im really trying to understand so thats why I ask questions

Answer 10

the units of joules are kg * (m/s^2) so we need to convert from hours to seconds

Answer 11

ohh because we havew to have seconds

Answer 12

okay i understand

Answer 13

oh, I forgot, we need to convert from km to meters but that's just a simple 1000 * multiplication

Answer 14

anyway multiplying all that out gives us

8 * 1.61 * 1000 / (60*60) = 3.57777....cont. m/s

Answer 15

now, since units of joules need kg not pounds we do another conversion to get 23.9 lb to kg

Answer 16

multiplying all that out gives (23.9/1000)*454 = 10.8506kg

Answer 17

thankfully it's the easy part now

1/2 mv^2 = (1/2)(10.8506)( 3.57777)^2

Answer 18

are you dividing it by 1000 because you want it to go from grams to kilograms?

Answer 19

yes

Answer 20

69.44621722

Answer 21

yup and since we have three sig figs we round that to 69.4