A possible spike in the number of impacts in the inner solar ...

[tichca]

A possible spike in the number of impacts in the inner solar system about 4 billion years ago may have mostly likely been due to
 
  A) the passage of another star close to the Sun
  B) planetary migration caused by the shifting of the orbits of the Jovian planets
  C) the giant collision that formed the Moon
  D) the breakup a planet to form the asteroid belt

Question 2

How much power does a sphere with a radius of 10 cm radiate if is has an emissivity e = 1.0 and is kept at a temperature of 400 K? The Stefan-Boltzmann constant is 5.67  10-8 W/(m2K4).
 
  A) 60 W
  B) 70 W
  C) 180 W
  D) 210 W
  E) 360 W

[ambernicolefink]

Answer to Question 1

B

Answer to Question 2

C

[tichca]

Thanks for the timely response, appreciate it

[Viet Thy]

Great answer, keep it coming