Question

An asteroid with a mass of 5.0 x 105 kg collides with the Earth and slides horizontally along the ground without bouncing (not actually possible but just pretend). The velocity of the asteroid before impact is 1.1 x 104 m/s and the coefficient of kinetic friction between the asteroid and the Earth is 1.80.
How much energy is lost due to friction between the asteroid and the Earth after the asteroid has come to rest?

Answer 1

The strength of the friction doesn't matter. Neither does the distance or the time the asteroid takes to stop. All that matters is that the asteroid has

1/2 (mass) (speed squared)

of kinetic energy when it lands, and zero when it stops.
So

1/2 (mass) (original speed squared)

is the energy it loses to friction in order to come to rest.