/sci/ - Science & Math

bump for stupid

>>5240683
F=MA.
Glider 1 decelerates as glider 2 accelerates.
No energy is lost.

You should be able to figure it out from that.

>>5240689
There is no implied acceleration in this equation, meaning you're proposing that the force is zero? This is a momentum equation, by the way.

>>5240689

Pic related.
>>5240683

Read up on momentum and its formulas.

>>5240694
I have read up on it, but I need help tackling this problem specifically as it generally reflects the nature of the problem on the test.

lol this is hs physics

Since it's elastic, you can use both momentum and energy equations to solve (either or), to lazy to type the formula

>>5240695

Have you drawn a picture of what's going on?

mv+mv=mv+mv
Plug all the shit you know in
(100)(10)+(200)(0)=(100)(3.33)+(200)(v)
Solve for shit.

The second part is common sense.

>>5240683

Assume that momentum is conserved..

m1v1 = m1v1` + m2v2`

100*10 = 100*(-3.33) + (200)(v2`)

also kinetic energy must be conserved because it's elastic

>>5240696
When I use momentum, I get that the P of the moving glider is 1000 J, (100 g * 10 cm/s), and the combined momentum is 1000 J as well since the P of the stationary glider is 0. But I don't know how to apply that to the final velocity of the larger glider after the collision.

>>5240702
Unless you really want to know the vector, the negative isn't necessary.

>>5240702
So 6.66 cm/s? So is that what the implication of elasticity is, that the velocity is preserved and split between the two? Although how can the 200g glider be moving faster than the 100g after the collision?

>>5240713
cm*

>>5240699
So they both move away from each other at 3.33 m/s?

>>5240704

What the hell are you doing son?

>>5240711

yea I assumed that the original direction of the puck was positive, hence, it's final velocity would be negative.

Elastic implies that the total kinetic energy of the system is conserved, you could solve this using kinetic energy

KE = KE`
0.5m1(v1)^2 = 0.5m1(v1)^2 + 0.5m2(v2)^2
you wouldn't need the negative here, since it's a scalar equation

>>5240720

sorry should be

0.5m1(v1)^2 = 0.5m1(v1`)^2 + 0.5m2(v2`)^2

and your question

>So 6.66 cm/s? So is that what the implication of elasticity is, that the velocity is preserved and split between the two? Although how can the 200g glider be moving faster than the 100g after the collision?

it means the kinetic energy was transferred to the 200g puck, that's why it's velocity increased. The 100g puck lost kinetic energy, so you expect it to slow down.

>>5240726
So to explain the kinetic and momental conservation I can describe it as 10 cm/s initial velocity dropping to 6.66 cm/s when subtracting the final velocity of 3.33 cm/s?

>>5240731

no, the numbers just worked out that way. You want to look at energy, not velocities.

>>5240735
Does v2 stand for the unknown velocity of the 200g glider or the final velocity of the 100g glider?

>>5240693
What?
Considering they move on a single plane, one glider decelerates from 10 to -3.3 cm/s.
The other accelerates from 0 to X cm/s.

How are you too dumb to wrap your head around this?

STOP HELPING HOMEWORK FAGGOTS, THIS IS WHY THEY COME

The answer is 5m/s. I know cuz i plugged it into wolfram.