Answer :
Answer:
4.05 m/s
Explanation:
Energy is conserved, so the sum of the sphere's initial potential energy and initial translational kinetic energy must equal the sum of the sphere's final translational kinetic energy and final rotational kinetic energy.
PE₀ + KE₀ = KE + RE
mgh + ½ mu² = ½ mv² + ½ Iω²
Moment of inertia for a sphere is I = ⅖ mr². For rolling without slipping, v = ωr.
mgh + ½ mu² = ½ mv² + ½ (⅖ mr²) ω²
mgh + ½ mu² = ½ mv² + ⅕ mv²
mgh + ½ mu² = ⁷/₁₀ mv²
gh + ½ u² = ⁷/₁₀ v²
Solve for v:
v² = ¹⁰/₇ (gh + ½ u²)
v² = ¹⁰/₇ [ (9.8 m/s) (2.00 m sin 29.0°) + ½ (2.00 m/s)² ]
v = 4.05 m/s