Answer: Delta U = 30 - 80; -50 jules
Explanation:
The system is losing 80 J, but it is also gaining 30 J because the surroundings are doing work on it. So the net change in energy is -50 J
The formula for speed is:
Speed = Distance/Time
We can plug in the given values into the above equation:
Speed = 570m÷24s
Speed = 23.75, which rounds to 24m/s as a whole number. Therefore, the answer is b.