Two balls, a and b, collide and stick together. ball a has a mass ma and ball b has a mass mb. before the collision ball a is moving in the +x direction with speed va and ball b is moving in the -y direction with speed vb . for what conditions are the two balls motionless after the collision? a. ma = mb
b. va = vb
c. mava = mbvb
d. mava = -mbvb
e. there is no such condition

radiation

explanation:

heat is transmitted by radiation

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.