A train engine of mass 15000kg , traveling with speed of 90km/hr has same kinetic energy as a car moving parallely the same speed . find the mass of the car​

since you're a real machine, your ama is always less than your ima, because you can never totally eliminate friction.

when heated, the valance electrons increased their speed and transferred the heat from electron to electron.   i just took the test.

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.

the answer to this is proletariats.

hope this : )