AP Physics 1: 3.3 Fields in Space

Maybe if the dinosaurs had paid more attention in AP Physics, they could've figured out a way to avoid that pesky extinction problem. Oh well. Solve this question in fond memory of all the dinosaurs. 

AP Physics 1Fields in Space
LanguageEnglish Language
Science Practice 3Engaging in scientific questioning

Transcript

00:22

thousand kilometers away from the center of the earth

00:25

what's the magnitude of gravitational force that the earth exerts on the

00:30

asteroid huh and here the potential answers....... Igor is stressed but we

00:36

can't blame him, there's an asteroid out there and he needs to make sure [Asteroid heading towards Earth]

00:39

everything stays groovy here on earth now in order to answer this question we

00:44

need to remember the formula to figure out gravitational force that equation

00:48

goes a little something like this gravitational force is equal to the [Gravitational force equation appears]

00:51

gravitational constant G times the mass of the larger object M divided by the

00:59

square of the distance between the objects that distance here is the radius

01:03

which is shown as R in the equation right there so GM over R squared now the

01:08

question doesn't tell us what the mass of the earth is the only number we know

01:12

for sure is the distance between the asteroid and the center of the earth

01:15

which is 20,000 kilometers so we need to square that number in order to calculate

01:20

the gravitational force but wait we need to convert those kilometers into meters

01:25

we've got to use standard units because well they're standard for a reason [standard units appear]

01:29

20,000 kilometers is 20 million meters and 20 million squared is 400

01:35

quadrillion so the correct answer here is D) and boy that's a whole lot of

01:40

meters now to answer question like this we need to memorize the equation there's [Boy's head opens and equation appears]

01:43

no way around it people now listen carefully...G equals GM over R squared G

01:50

equals GM over R squared...... G equals GM over R squared

02:00

and now we're starting to understand why scientists go mad