1.
By Conservation of momentum
M1V1i + M2V2i =
M1V1f+ M2V2f
0.2*0.5+0.5*0 = 0.2*V1f +0.5*0.286
V1f = -0.215 m/s
Initial Kinetic energy is
Kinitial =
(1/2)M1V1i2
+(1/2)M2V2i2
=(1/2)(0.2)(0.5)2 +(1/2)(0.5)(0)2=0.025 J
Final Kinetic energy is
Kfinal=
(1/2)M1V1f2
+(1/2)M2V2f2
=(1/2)(0.2)(-0.215)2
+(1/2)(0.5)(0.286)2=0.025 J
Since Kinitial = Kfinal
,KInetic energy is conserved
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2.
By Conservation of momentum
M1V1i + M2V2i =
M1V1f+ M2V2f
0.5*0.45+0.5*0 = 0.5*0.225+0.5*V2f
V2f = 0.225 m/s
After the collision the masses move with the same velocity in
same direction.
Initial Kinetic energy is
Kinitial =
(1/2)M1V1i2
+(1/2)M2V2i2
=(1/2)(0.5)(0.45)2 +(1/2)(0.5)(0)2=0.050625
J
Final Kinetic energy is
Kfinal=
(1/2)M1V1f2
+(1/2)M2V2f2
=(1/2)(0.5)(0.225)2
+(1/2)(0.5)(0.226)2=0.0253125 J
Since initial kinetic energy Kinitial is not equal to
final kinetic energy Kfinal.The Collision is
Inelastic
