Question 1 - Treball, energia i energia potencial · Física I URV 2023

Tema: Treball, energia i energia potencial · Del examen Examen Física I (1ª Convocatoria - Enero 2023) (2023)

Enunciado

A crate of mass m=20 kgm = 20\text{ kg} is pulled up a ramp inclined at an angle of 30∘30^\circ with respect to the horizontal to reach an elevation of h=3 mh = 3\text{ m}. The pulling force is applied via a rope with a tension of F=200 NF = 200\text{ N} forming an angle of 45∘45^\circ above the incline surface. The kinetic friction coefficient between the crate and the plane is μk=0.2\mu_k = 0.2. (Take g=9.8 m/s2g = 9.8\text{ m/s}^2).

b.

Compute the work carried out by the applied force FF during this ascent. Will this work be equal to the work done by friction? Compute the work of friction and compare both values.

Enunciado: Question 1 - Treball, energia i energia potencial · Física I URV 2023

Solución

Según los criterios oficiales de corrección

Work carried out by the applied force F during this ascent

Solución: 848.53848.53 J / 0.8490.849 kJ

Work of friction

Solución: −33.98-33.98 J / −0.034-0.034 kJ

Will this work be equal to the work done by friction? Compute the work of friction and compare both values.

Solución: No, they are completely different. WFW_F is positive (≈+848.5 J\approx +848.5\text{ J}) delivering external energy, while WfrictionW_{\text{friction}} is negative (≈−34.0 J\approx -34.0\text{ J}) dissipating energy as heat. The remainder of WFW_F goes into increasing potential energy (ΔU=mgh=588 J\Delta U = mgh = 588\text{ J}) and kinetic energy (ΔK=mad≈226.5 J\Delta K = mad \approx 226.5\text{ J}).

La explicación paso a paso, hecha con IA, es Premium. Premium

Resuélvelo aquí mismo: corrección automática, pistas y solución paso a paso.

‹ Ejercicio Exercise 1 · 2024 · Ejercicio 2 - Problema (Parcial Nov 2021) · 2021 ›

Más ejercicios de Treball, energia i energia potencial