Question

In 1990, walter arfeuille of belgium lifted a 281.5 kg object through a distance of 17.1 cm using only his teeth

(a) how much work was done on the object by arfeuille in this lift, assuming the object was lifted at constant speed?

Answer 1

im thinking \[-\Delta U_{GRAV}?\]

Answer 2

Right-o!

Answer 3

so \[\implies -(281.5)(9.8)(0-0.171)?\]
i change this to meters right?

Answer 4

0.171 is in metres already. I don't get your question.

Answer 5

that multiplication is the answer though..

Answer 6

the given was 17.1

i was confirming that i needed to change that to meters

Answer 7

or do i use 17.1?

Answer 8

ah, yes, it is 0.171 that you need you need to use.

Answer 9

ahh thanks

Answer 10

His work was used to increase potential energy of the weight, therefore you can calculate like W=mgh=281.5x9.81x0.171 J

I have heard that the work done later on by his dentist to fix his dentures was quite hard

Answer 11

a follow up question was

(b) What total force was exerted on arfeuille's teeth during the lift

what does that mean?

Answer 12

The forced exerted was exactly F=mg=281.5 x 9.81 Newtons

Answer 13

It means that a downward force equal to the weight he lifted will be exerted on his teeth (the contact point).

Answer 14

Btw, @CarlosGP, I saw a man on TV lift a 1000kgs (a ton) with his teeth. Jus sayin.

Answer 15

I saw another one make the Statue of Liberty disappear! ;) Can you believe it?

Answer 16

but this was for real. It was on 'Superhuman' on the DISCOVERY CHANNEL!

Answer 17

I have to see under which conditions was the test carried out. I am not too sure neck muscles can stand that force

Answer 18

I'll try to find a video..

Answer 19

@rajathsbhat, I would appreciate it! Thanks!

Answer 20

so for (b) it's just gravitational force?

Answer 21

@rajathsbhat

Answer 22

yes. Sorry, I was busy searching for that vid.

Answer 23

haha lol...

Answer 24

and yes, it is the gravitational force.

Answer 25

thanks!!`

Answer 26

yw.