A 3 kg object moves in a horizontal circle of radius 2 m at a constant speed of 4 m/s. Find the centripetal force.
Answer and explanation
Correct answer: D. 24 N
- Step 1: Centripetal force F = m v^2 / r.
- Step 2: F = 3 x 4^2 / 2 = 24 N.
Answer
24 N.
Why not the others: '6 N' uses mv/r instead of mv^2/r; '96 N' multiplies by r instead of dividing; '12 N' includes a factor 1/2 from kinetic energy.
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