Question

Most geologists believe that the dinosaurs became extinct 65 million years ago when a large comet or asteroid struck the earth, throwing up so much dust that the sun was blocked out for a period of many months. Suppose an asteroid with a diameter of

5.0km and a mass of 2.5

Answer 1

a)
Ma (asteroid)= 2.5*10^14 kg
Da (diameter/asteroid)= 5000m
Va =4.0*10^4 m/s
Me (earth)= 5.98*10^24 kg
Ve=0

because this is an elastic collision meaning it doesn't bounce off.

This is your equation: Ma*Va= (Ma+Me) Vf
solving for Vf we get

Vf=(Ma*Va)/(Ma+Me)
   2.5*10^14*4*10^4/2.5*10^14+5.98*10^24

= 10^19/10^14(2.5+ 5.98*10^10)
= 10^19/5.98*10^23
= 1.67*10^-4 m/sec

b) 1.67*10^-4/1.5*10^11

=1.11*10^-15