Question

Quick Physics Questions! Will give medal!!
Which of these is the best example of an elastic collision?
A rubber ball is dropped from 1.2 m and bounces back up to a height of 0.8 m.

A billiard ball strikes another of the same mass at rest and stops, and the second ball then moves with the same velocity as the first ball.

A cart rams a similar cart and latches onto it with a loud clack.

A cart rams another with a compressed spring, which is released, pushing them apart.
Two objects, A and B, each of mass 0.22 kg, are moving at 0.52 m/s directly toward each other. A completely inelastic collision occurs and both objects stop. What percentage of the total kinetic energy is changed into other forms of energy?

Answer 1

Like I said in PM--I'm not too good with Physics, I'm only taking Bio as a freshman, but I'd say A or C.

Answer 2

oh it's ok :)

Answer 3

@wolfe8

Answer 4

I think A is the best example. C shows the same as A but doesn't explicitly say that the cart moved at exactly the same speed after hitting the spring as it did when it hit the spring.

Answer 5

I thought it was B because one of the examples for elastic collision in my book was billiard balls

Answer 6

oh . I meant B . I didn't say the rubber ball question because it was in the first paragraph :\

Answer 7

see*

Answer 8

A billiard ball strikes another of the same mass at rest and stops, and the second ball then moves with the same velocity as the first ball.

CUZZ no energy was lost. I think that is what ellastic means.

Answer 9

^ that is what I was trying to say lol

Answer 10

when there is an elastic collison, there is both conservation of energy and momentum

Answer 11

linear momentum! not angular

Answer 12

oh lol so I was right on B for the first question?

Answer 13

ok onto the second and last question the answer choices are : 0 percent

25 percent

50 percent

100 percent

Answer 14

wait did I just see a comment about a cart?

Answer 15

100 :D

Answer 16

\[\huge m_1v_1 + m_2v_2=(m1+m2)v_f\]
m1=m2
v1=v2
so some of that cancels

Answer 17

they collide and they stop completly means that they collided and all of it went from kinetic to Heat

Answer 18

umm, @QueenBee232 are you taking classical physics or modern physics?

Answer 19

that is classical @roadjester

Answer 20

there's an important difference in modern physics
in modern, when there is a inelastic collision, all energy is conserved

Answer 21

in classical, kinetic energy is not conserved

Answer 22

It's classical lol.

Answer 23

hey, I'm taking modern physics,
SUE ME!

Answer 24

lol I think it might be modern but not really sure lol

Answer 25

so for the first question I have answer B and for the second..?

Answer 26

in modern physics, things move near speed of light, i just noticed ur only going at 22 m/s

Answer 27

my bad

Answer 28

ok so what would be the answer for the second question?

Answer 29

kind of confused

Answer 30

I know it can't be 0 though

Answer 31

@roadjester

Answer 32

need to go to sleep soon

Answer 33

.....

Answer 34

can someone help me please?

Answer 35

I know the first answer need the second though

Answer 36

@Fizzerino

Answer 37

2 more minutes

Answer 38

@roadjester

Answer 39

....

Answer 40

wow

Answer 41

going to go with @timo86 s answer

Answer 42

huh sorry what? was helping my mom

Answer 43

Clearly, there was kinetic energy before the collision and none after, so 100% of the KE was converted. Classically.