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> hey anon, wanna give your opinion?
asd
#95 to #3

jackraptor
Reply 0 123456789123345869
(10/07/2013) [] thumbs up for kermit t. frog here
#5

Lunchboxman
Reply +46 123456789123345869
(10/06/2013) [] as someone who has worked on cgi in their lifetime, this has all the telltale signs.
#16

EhBud
Reply +17 123456789123345869
(10/07/2013) [] but all objects fall at the same rate so this wouldn't happen
#72 to #16

redthumbmaster
Reply 0 123456789123345869
(10/07/2013) [] But weight does affect how a ping pong ball can bounce. If you filled a ping pong ball with sand it wouldn't bounce the same. Also if you look at how he throws the ping pong balls up they aren't all released from the trays at the same time also they are stacked on each other. Despite all this, it is fake and you can clearly see how the cgi looks off compared to real world physics.
#19 to #16

danielsturk [OP]
Reply +4 123456789123345869
(10/07/2013) [] Only in a vacuum, e.g. not earth
#21 to #19

mylazy
Reply +1 123456789123345869
(10/07/2013) [] Don't worry mate. You are probably going to be thumbed down but you are right. Since we have enough people who only payed attention to one part of their 6th grade science class, it is a simple thing called airresistance. If everything fell at the same rate here on earth parachutes would be useless. Paper airplanes wouldn't hover. Paper would fall at the same pace that a pencil did. Like I said, daniel is right. It only works in a vacuum that they fall at the same rate. A piece of paper will fall at the same rate as a pencil, if you get rid of atmosphere. Parachutes would do nothing on Earth without our atmosphere (though that is kind of a moot point since we would never have existed without the atmosphere). And believe it or not...weight has an affect. Weight, surface area, shape, etc. all affect the acceleration of the fall.
#35 to #30

mitchr
Reply 0 123456789123345869
(10/07/2013) [] Is it? I'd assume the equation's something involving shape and surface area as well as weight, and a ping pong ball being round, it doesn't seem like shape would have anything, nor would surface area, it being small.
But then again, kinetic energy is ke=m*(v^2)
So I suppose it could be either way. ANybody have the exact equation?
But then again, kinetic energy is ke=m*(v^2)
So I suppose it could be either way. ANybody have the exact equation?
#52 to #36

guidedhand
Reply 0 123456789123345869
(10/07/2013) [] this is a potential energy problem. The kinetic energy of the ping pong ball must be able to 'push' the air out of the way. If the ball is heavier and is through up wiht the same speed as one of the other balls, its will be able to rise higher on its bounce as it will have higher mechanical energy. So the z component is sound reasoning, however the lining up in the x and y? nuh uh.
#66 to #52

anon id: 91d2ba67
Reply 0 123456789123345869
(10/07/2013) [] This is a forces problem:
F(drag) = cv^2 (approximately)
where c is a constant based on shape, size and other factors and v is velocity and the direction of the force is opposite to the direction of velocity.
F(weight) = mg
where g is 9.81m/s and m is the mass of the object in kg.
the acceleration on the ball is caused by the net force (F(weight)  F(drag)) then acceleration of an object in air can be found using newtons 2nd law F=ma
so: a = Fnet/m = ((mg)(cv^2))/m
if there is no atmosphere c = 0 since c is proportional to fluid (in this case air) density
so: a = mg/m = g, ie. acceleration under gravity is just a constant
source: First Year Bachelor of Engineering
F(drag) = cv^2 (approximately)
where c is a constant based on shape, size and other factors and v is velocity and the direction of the force is opposite to the direction of velocity.
F(weight) = mg
where g is 9.81m/s and m is the mass of the object in kg.
the acceleration on the ball is caused by the net force (F(weight)  F(drag)) then acceleration of an object in air can be found using newtons 2nd law F=ma
so: a = Fnet/m = ((mg)(cv^2))/m
if there is no atmosphere c = 0 since c is proportional to fluid (in this case air) density
so: a = mg/m = g, ie. acceleration under gravity is just a constant
source: First Year Bachelor of Engineering
#77 to #66

seekerofpie
Reply 0 123456789123345869
(10/07/2013) [] Also i had to log in to finish this.
This way you can find the acceleration over time and then you can use differentiation and some magic maths that i cbf explaining or remembering to find the final velocity when acceleration is non constant. Then using E(kinetic) = mv^2 you can find the energy of the ball. You can then (assuming no energy is lost on bouncing or knowing the energy lost on bouncing) use this along with Work = Fd to find the height the ball will bounce too by replacing the Work with the previously calculated Ek and the F with the previous maths only Fnet = F(weight) + F(drag) (since they now both go down since gravity is down and drag is opposite to the upwards velocity) and then:
Ek/Fnet = d.
where d is the height in meters.
Again Source is Engineering
This way you can find the acceleration over time and then you can use differentiation and some magic maths that i cbf explaining or remembering to find the final velocity when acceleration is non constant. Then using E(kinetic) = mv^2 you can find the energy of the ball. You can then (assuming no energy is lost on bouncing or knowing the energy lost on bouncing) use this along with Work = Fd to find the height the ball will bounce too by replacing the Work with the previously calculated Ek and the F with the previous maths only Fnet = F(weight) + F(drag) (since they now both go down since gravity is down and drag is opposite to the upwards velocity) and then:
Ek/Fnet = d.
where d is the height in meters.
Again Source is Engineering
#71 to #66

guidedhand
Reply 0 123456789123345869
(10/07/2013) [] except c =/= 0 thats the whole point of this question. a is also =/= g.
Sources:second year Physics.
Sources:second year Physics.
#81 to #71

seekerofpie
Reply 0 123456789123345869
(10/07/2013) [] Well all the maths i stated would work independent of whether c is zero or not, i was just adding that as a note for the people talking about no air earlier. You would just have to work out c but it has big complicated formulae which we havn't studied yet
en.wikipedia.org/wiki/Drag_(physics)
en.wikipedia.org/wiki/Drag_(physics)
#83 to #81

guidedhand
Reply 0 123456789123345869
(10/07/2013) [] if c is zero, then all of the balls would just fall at the same rate tho, making your calculations kinda useless :/ there would be no way to distinguish between them all
#2

zysolyn
Reply +16 123456789123345869
(10/06/2013) [] he threw them in the air at random, plus they left the screen before bouncing back up. Obvious fake is obvious.
#46 to #28

wesleyhathaway
Reply +7 123456789123345869
(10/07/2013) [] **wesleyhathaway rolls 00**