- #1
lala56
- 6
- 0
"A 10.0 g marble slides to the left with a velocity of magnitude 0.600 m/s on the frictionless, horizontal surface of an icy, New York sidewalk and has a head-on elastic collision with a larger 25.0 g marble sliding to the right with a velocity of magnitude 0.250 m/s (Fig. 8.35)."
I need to "Calculate the change in kinetic energy (that is, the kinetic energy after the collision minus the kinetic energy before the collision) for each marble."
So, I will start with the 25g marble going right, which hits the 10g marble and revserses direction to go left
I correctly found the velocity of the 25g marble after the collision, it is -.24.
Now, to find the change in kinetic energy, i did this:
v1=intial velocity
K2-K1=.5mv^2 - .5mv1^2
.5(.025)(-.24)^2 - .5(.025)(.25)^2
isn't this how one is supposed to find change in kinetic energy? Then why is it incorrect? did i go wrong with the positive negative sign?
this one should be negative right?
thankyou
I need to "Calculate the change in kinetic energy (that is, the kinetic energy after the collision minus the kinetic energy before the collision) for each marble."
So, I will start with the 25g marble going right, which hits the 10g marble and revserses direction to go left
I correctly found the velocity of the 25g marble after the collision, it is -.24.
Now, to find the change in kinetic energy, i did this:
v1=intial velocity
K2-K1=.5mv^2 - .5mv1^2
.5(.025)(-.24)^2 - .5(.025)(.25)^2
isn't this how one is supposed to find change in kinetic energy? Then why is it incorrect? did i go wrong with the positive negative sign?
this one should be negative right?
thankyou