If a freely falling rock were equipped with a speedometer, by how much would itd speed readings increase with each second if it were on a planet wreg=20m/s2?
" 20 m/s² " means that if gravity is the ONLY force on the object (the object is in 'free fall'), then its speed increases by 20 m/s every second.
That's the answer to your question. Now, let me ask you another one:
How does a speedometer tied to a falling rock work ? How can it measure the rock's speed ?
Maybe one way would be to have a little tiny propeller on the front of the speedometer, and it could measure how fast the propeller is spinning as the rock falls through the air ? Great idea. But we already said the rock is in free-fall, so there's no air resistance, we can't have any air, and there's nothing to spin the propeller.
How would you do it ? How can you measure the rock's speed ?
