
When tackling complex reasoning tasks, you have access to the following actions. Use them as needed to progress through your thought process.

[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

You should strictly follow the format below:

[ACTION NAME]

# Your action step 1

# Your action step 2

# Your action step 3

...

Next action: [NEXT ACTION NAME]


system
A massive vertical plate is fixed on a car moving at a speed of $4 \ \mathrm{m/s}$. A ball is approaching the plate with a speed of $5 \ \mathrm{m/s}$ relative to the Earth. Determine the speed of the ball relative to the Earth after a perfectly elastic normal collision.

Present the answer in LaTex format: \boxed{Your answer}
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