Answer:
a) 9 - 1.2 = 7.8 N
b) Since the force exerted by the box is it's weight, it acts in a downward direction. So the box will exert a force downward (perpendicular to the horizontal surface).
Explanation:
A 9N block would exert 9N of normal force on the horizontal plane under normal conditions. But in this case, we have a spring taking away some of the force by applying an upward force on the box.
So the force exerted by the box on the surface would now be:
a) 9 - 1.2 = 7.8 N
b) Since the force exerted by the box is it's weight, it acts in a downward direction. So the box will exert a force downward (perpendicular to the horizontal surface).
I think the complete question is:
An old movie poster used a quote "In space, no one can hear you scream!" Which of these best explains the quote?
A) The quote is incorrect, you can hear sound in outer space.
B) Sound cannot be polarized. So, you cannot hear sound in space.
C) Sound is an electromagnetic wave and needs no medium to travel through.
D) Sound needs a medium for the wave to vibrate and there is nothing in space to vibrate.
Answer:
D) Sound needs a medium for the wave to vibrate and there is nothing in space to vibrate.
Explanation:
There are two types of waves:
- Mechanical Waves : These waves requires are medium to travel from one point of space to another point of space. Sound wave is one such example. Since they depend upon medium so speed of travelling also depend upon medium.
- Electromagnetic Waves : These type of waves do not require a medium to travel. If medium exists then it will cause some hindrance in there path but still they will travel. For example: Light waves, X-Rays, Microwaves, Infrared waves, Ultraviolet waves etc.
In space no particle exists so no mechanical waves, such as sound, can travel through it but any electromagnetic wave can travel, such as light. That is why when astronauts are in space walk or when they are in outer space then they do not talk rather they use sign language to communicate
En términos simples, una articulación (donde dos o más huesos se unen) forma el eje (o fulcro), y los músculos que cruzan la articulación aplican la fuerza para mover un peso o resistencia. Las palancas suelen estar etiquetadas como de primera, segunda o tercera clase
Flat on her back, her whole body would be against the floor and she wouldn't have to do anything to hold herself up.
Answer with Explanation:
We are given that
Length of wire 1=
Length of wire 2=
Resistivity of copper wire=
Resistivity of aluminum wire=
Wire 1=Copper wire
Wire 2=Aluminum wire
Diameter of both wires are same and resistance of both wires are also same.
We know that
Resistance =
When diameter of wires are same then their cross section area are also same .
When resistance and area are same then the length of wire depend upon the resistivity of wire .
The length of wire is inversely proportional to resistivity.
When resistivity is greater then the length of wire will be short and when the resistivity is small then the length of wire will be large.
Therefore, 
Hence, the length of wire 1 (copper wire) is greater than the length of wire 2 (aluminum).
