Question A – Physics

Two balls, stacked together as illustrated below, are released from a certain height. The ball on the bottom has a mass of 1000kg and the ball on the top has a mass of 1kg. Upon impact, the balls both have a speed of 10m/s. Assuming all collisions are elastic, what is the speed of the small ball after impact, rounded to the nearest whole number?


  • All frames of reference are equal. 
  • The mass of the small ball is negligible compared to the mass of the big ball, or, alternatively, the mass of the large ball can be seen as infinite. 

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Question 2 – Logic/CS

Given that there is only one correct answer for this question, which one is the correct answer? 

  1. Neither 2 nor 3 is the correct answer.
  2. Neither 3 nor 4 is the correct answer. 
  3. Trust me, this is the correct answer. 
  4. Neither 1 nor 2 is the correct answer. 

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