A0.1 kg object initially moving with a velocity of 0.2 m/s makes an elastic head-on collision with a 0.15 kg object initially at rest. what percentage of the original kinetic energy is retained by the 0.10-kg object?

4 %

Explanation:

mass of the object 1, m₁ = 0.1 Kg

initial velocity of object 1,v₁= 0.2 m/s

mass of object 2, m₂ = 0.15 kg

initial speed of the object 2. v₂ = 0 m/s

Kinetic energy retained by the object 1 = ?

using the formula to calculate velocity of the ball after collision

negative sign represent the velocity  is in opposite direction after collision.

Initial KE

final KE

% of KE retained

=

=

= 4 %

the percentage of Kinetic energy retained after collision is equal to   4 %

i believe the answer is a hope it and is correct

speed of light in vacuum is 300,000 km/s

speed of light in other mediums is given by the expression v = c/n, where c is the speed of light in vacuum and n is the refractive index of medium.

for the first medium v = 200,000 km/s

  so, refractive index of medium = 300000/200000 = 1.5

    1.5 refractive index is usually for glass. so first medium is glass.

for the second medium v = 250,00 km/s

so, refractive index of medium = 300000/250000 = 1.2

    1.2 refractive index is usually for water. so second medium is water.

for the third medium v = 0 km/s

so, refractive index of medium = 300000/0 = ∞

    ∞ refractive index is usually for opaque mediums. so third medium is opaque medium.