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Aleks04 [339]
3 years ago
7

Un repartidor de comida rápida entrega una pizza a una casa que se encuentra a 20 km de distancia y se demora 20 minutos en lleg

ar. De vuelta a la pizzería vuelve más relajado y se demora media hora. ¿Cuál fue su velocidad media en el trayecto completo?
Physics
1 answer:
Alex_Xolod [135]3 years ago
6 0

Answer:

La velocidad media en el trayecto completo es 0.8 \frac{km}{minutos}.

Explanation:

La velocidad es una magnitud física que expresa la relación entre el espacio recorrido por un objeto y el tiempo empleado para ello.

En otras palabras, la velocidad es una magnitud que relaciona el cambio de posición (o desplazamiento) con el tiempo.

La velocidad media resulta del cociente entre el desplazamiento seguido por un móvil y el  tiempo transcurrido que se emplea  para realizar dicho desplazamiento:

velocidad=\frac{desplazamiento}{tiempo}

En este caso, un repartidor de comida rápida entrega una pizza a una casa que se encuentra a 20 km de distancia y se demora 20 minutos en llegar. De vuelta a la pizzería vuelve más relajado y se demora media hora. Entonces, el desplazamiento total entre la pizzería y la casa será 40 km, considerando que se dirige a la casa y vuelve a la pizzería.

Por otro lado, el tiempo total será el tiempo en que se dirige a la casa y luego vuelve a la pizzería, es decir 20 minutos + 30 minutos= 50 minutos.

Entonces:

velocidad=\frac{40 km}{50 minutos}

Resolviendo:

velocidad= 0.8 \frac{km}{minutos}

<u><em>La velocidad media en el trayecto completo es 0.8 </em></u>\frac{km}{minutos}<u><em>.</em></u>

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\vec{P}_f = (2.850 \ kg \ ) *  ( \ 14.617 \frac{m}{s} \ , \ 6.508 \frac{m}{s} \ )

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As there are not external forces, the total linear momentum must be constant.

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\left \{ {{m_{truck} \ v_{truck} = 41,658.45 \frac{ kg \ m}{s}  } \atop {m_{car} \ v_{car}=18,547.8 \frac{kg \ m}{s} }} \right.

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1900 \ kg \ v_{truck} = 41,658.45 \frac{ kg \ m}{s}

v_{truck} = \frac{41,658.45 \frac{ kg \ m}{s}}{1900 \ kg}

v_{truck} = \frac{41,658.45 \frac{ kg \ m}{s}}{1900 \ kg}

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950 \ kg \ v_{car}=18,547.8 \frac{kg \ m}{s}

v_{car}=\frac{18,547.8 \frac{kg \ m}{s}}{950 \ kg}

v_{car}=19.524 \frac{m}{s}

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