20.4 years is 20.4/10.2 = 2 half-life cycles, which means a quarter of the starting mass or 15.2 g will remain after this time.
Answer:
this is because the light rays get reflected irregularly
Explanation:
If you do this on Earth, then the acceleration of the falling object is 9.8 m/s^2 ... NO MATTER what it's mass is.
If its mass is 10 kg, then the force pulling it down is 98.1 Newtons. Most people call that the object's "weight".