Two objects with masses of 1kg and 2kg collide frontally and stop. What is the ratio of their of their kinetic energies before colliding?
Con of momentum:
Initial momentum = final momentum
M1*v1i + m2*v2i = 0
V1i = -m2/m1*v2i
I'll set m1 = 1 kg, m2 = 2 kg
V1i = -2*v2i
Ratio = KE1i/KE2i
Ratio = (1/2*m1*v1i^2)/(1/2*m2*v2i^2)
With m1 and m2 subbed in
Ratio = 1/2*v1i^2/v2i^2
Sub in v1i = -2*v2i
Ratio = 1/2*(-2*v2i)^2/v2i^2
Ratio = 2
So KE1i = 2*KE2i
That's what I got.
Hope the explanation helped
if they both stop dead, their kinetic energies were equal. this implies that their relative velocities were in the inverse proportion to their masses
im a freshman
Comments
Con of momentum:
Initial momentum = final momentum
M1*v1i + m2*v2i = 0
V1i = -m2/m1*v2i
I'll set m1 = 1 kg, m2 = 2 kg
V1i = -2*v2i
Ratio = KE1i/KE2i
Ratio = (1/2*m1*v1i^2)/(1/2*m2*v2i^2)
With m1 and m2 subbed in
Ratio = 1/2*v1i^2/v2i^2
Sub in v1i = -2*v2i
Ratio = 1/2*(-2*v2i)^2/v2i^2
Ratio = 2
So KE1i = 2*KE2i
That's what I got.
Hope the explanation helped
if they both stop dead, their kinetic energies were equal. this implies that their relative velocities were in the inverse proportion to their masses
im a freshman