Answer:
B. posititvely charged particles
Explanation:
Opposites attract to each other, and the same charge repels.
As a wave moves through a medium, particles are displaced and return to their normal position after the wave passes.
Explanation:
A wave is a traveling disturbance that carries energy from one location to another. All waves move in straight lines outward and away from the source of a disturbance. Like the radiating circular ripples, the waves of water carry energy away from where a rock was dropped into the pond.
Waves can move as a single pulse or as a continuous series of waves, carrying energy away from its source. A pulse is a single disturbance, wave, or ripple that moves outward from the point of disturbance. A train of waves are many waves emitted over and over again from a single source.
As waves travel through matter, they will temporarily displace the molecules or particles in matter up-and-down or side-to-side. Waves move the energy but they do not carry the matter with them longitudinally as they move through matter. Once the disturbance passes, the medium will return to its original state or position.
Therefore, as the waves move through a medium, particles are displaced and return to their normal position after the wave passes.
Scientists use the color of a star to determine its temperature.
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Answer:
a) q = 39.29 cm
, b) h ’= - 3.929 cm the image is inverted and REAL
Explanation:
For this exercise we will use the equation of the constructor
1 / f = 1 / p + 1 / q
where f is the focal length of the salad bowl, p and q are the distance to the object and the image
The metal salad bowl behaves like a mirror, so its focal length is
f = R / 2
f = 44/2
f = 22 cm
a) Suppose that the distance to the object is p = 50 cm, let's find the distance to the image
1 / q = 1 / f - 1 / p
1 / q = 1/22 - 1/50
1 / q = 0.0254
q = 39.29 cm
b) to calculate the size of the image we use the equation of magnification
m = h’/ h = - q / p
h ’= - q / p h
h ’= - 39.29 / 50 5
h ’= - 3.929 cm
the negative sign means that the image is inverted
as the rays of light pass through the image this is REAL
Answer:
a) 
b) 
c) 
d) 
Explanation:
Given:
- mass of the astronaut,
- vertical displacement of the astronaut,
- acceleration of the astronaut while the lift,
a)
<u>Now the force of lift by the helicopter:</u>
Here the lift force is the resultant of the force of gravity being overcome by the force of helicopter.
where:
force by the helicopter
force of gravity
b)
The gravitational force on the astronaut:
d)
Since the astronaut has been picked from an ocean we assume her initial velocity to be zero, 
using equation of motion:
c)
Hence the kinetic energy:
