Answer:
b)
Explanation:
Normal force, is always directed upward the surface over which is placed the object, and can adopt any value, as required to meet Newton's 2nd Law.
In this case, as the external force on the suitcase pulls upward, in order to counteract the influence of gravity, normal force is less than the weight of the suitcase, as follows:
F + Fn = m*g
⇒ Fn = m*g - F
So, the normal force is equal to the magnitude of the weight of the suitcase (m*g) minus the magnitude of the force of the pull (F) which is the same expressed by the statement b.
The power of the engine is 320 W.
<u>Explanation:</u>
Power may be defined as the rate of doing work (or) work done per unit time. One unit of energy is used to do the one unit of work.
Power = Work done / Time taken
Given, Force = 80 N, height = 5 m , final velocity = 4 m/s
To calculate the power, we must know the time taken.
To find the time, use the distance and speed formula which is given by
Time = Distance / speed
Here distance = 5 m and speed = 4 m/s
Time = 5 / 4 = 1.25 s.
Now, Power = work done / time
= (F * d) / t = (80 * 5) / 1.25
Power = 320 W.
The standard unit of power is watt (W) which is joule per second.
Answer:
Los objetos A y C tienen cargas del mismo signo (opcion a)
Explanation:
Hay dos tipos de cargas
: cargas positivas y cargas negativas.
La Ley de Coulomb dice que la fuerza electrostática entre dos cargas puntuales es proporcional al producto de las cargas e inversamente proporcional al cuadrado de la distancia que las separa, y tiene la dirección de la línea que las une y se cumple que:
- La fuerza ejercida sobre una carga apunta hacia la otra cuando las dos tienen distinto signo (fuerza atractiva).
- El sentido de la fuerza se dirige hacia el lado opuesto de la carga cuando ambas tienen el mismo signo (fuerza repulsiva).
Es decir que las cargas de igual signo se repelen, mientras que las de diferente signo se atraen.
Entonces, si se juntan los objetos A y B y se repelen significa que la carga es del mismo signo.
Cuando se acercan los objetos B y C, se repelen. Entonces significa que posee carga de igual signo.
Por lo que podes concluir que <u><em>los objetos A y C tienen cargas del mismo signo (opcion a)</em></u>
The water cycle (hydro-logic cycle), explains the constant motion of water on, above and below the surface of the Earth. The mass of water on Earth stays equally constant over time, although the severe portion of the water goes into the major reservoirs of ice, fresh water, saline water and atmospheric water is variable depending on a wide range of climatic variables. The water moves from one reservoir to another, such as from river to ocean, or from the ocean to the atmosphere, by the physical processes of evaporation, condensation, precipitation, infiltration, surface runoff, and subsurface flow. In doing so, the water goes through different forms: liquid, solid (ice) and vapor.
