Problemas
(1) A 0.20-mathrm(kg) hockey puck initially traveling 5.0 mathrm(~m) / mathrm(s) is pushed on ice by a hockey stick with a constant force of 7.0 mathrm(~N) over a distance of 8.0 mathrm(~m) . Friction is negligible. Determine the final velocity of the hockey puck.
Roztwór
Norberto
avanzado · Tutor durante 1 años
4.2
(238 Votos)
Respuesta
To determine the final velocity of the puck, we can use the work-energy theorem, which states that the work done on an object is equal to the change in its kinetic energy.Given information:- Force applied on the puck: 7.0 N- Initial velocity of the puck: 5.0 m/s- Distance traveled by the puck: 8.0 mStep 1: Calculate the work done on the puck.Work = Force × DistanceWork = 7.0 N × 8.0 m = 56.0 JStep 2: Calculate the change in kinetic energy of the puck.Change in kinetic energy = Work doneChange in kinetic energy = 56.0 JStep 3: Calculate the final velocity of the puck.Initial kinetic energy = 1/2 × m × (initial velocity)^2Final kinetic energy = 1/2 × m × (final velocity)^2Change in kinetic energy = Final kinetic energy - Initial kinetic energy56.0 J = 1/2 × m × (final velocity)^2 - 1/2 × m × (5.0 m/s)^256.0 J = 1/2 × m × (final velocity)^2 - 12.5 J68.5 J = 1/2 × m × (final velocity)^2(final velocity)^2 = 137 m^2/s^2final velocity = √137 m/s ≈ 11.7 m/sTherefore, the final velocity of the puck is approximately 11.7 m/s.