Kinetic energy formula solves for speed

Steps:

• Kinetic energy KE = (1/2)mv², where m is mass and v is speed.
• Substitute values: 10 J = (1/2)(5.0 kg)v².
• Simplify: 10 = 2.5 v², so v² = 10 / 2.5 = 4.
• Take square root: v = √4 = 2 m/s.

Why C is correct:

• It matches the calculated speed from KE = (1/2)mv².

Why the others are wrong:

• A: Results from using v = √(KE/m) instead of the full formula.
• B: Comes from solving v² = KE/m, ignoring the 1/2 factor.
• D: Arises from doubling the correct v or misapplying the formula.

Final answer: C