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S_A_V [24]
3 years ago
5

Explain how we know dark matter exists if we cannot see it

Physics
1 answer:
Lubov Fominskaja [6]3 years ago
5 0

Answer:

Gravitational lensing is how we know there is dark matter

What this means is that the light is bending as the light travels from the source to the observer, and if there are any 'holes' in between the beam, that is where 'dark matter' exists

Explanation:

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Lexy throws a dart with an initial velocity of 25 m/s at an angle of 60° relative to the ground. what is the approximate vertica
Serjik [45]
An initial velocity is:
v o = 25 m/s
The vertical component of the initial velocity:
v o y = v o * sin 60° =
= v o * √3 / 2 = 25 m/s * √3 / 2 = 21.65 m/s
Answer:
The approximate vertical component of the initial velocity is 21.65 m/s.
7 0
4 years ago
Read 2 more answers
consider the photoelectric effect experiment. in one experiment yellow light shines on a piece of potassium metal. a current is
kompoz [17]

Explanation:

If the intensity of the yellow light increased, meaning more photons will strike the Potassium metal per unit area. This will cause more ejection of electrons from the metal and hence, the strength of current will also increase as we know that

I = Q/t, as the charge increase , the current will also increase.

4 0
3 years ago
What is the advantage in solving motion problems using energy conservation principles instead of free body diagrams
riadik2000 [5.3K]

Answer:

However, the disadvantages are:

1. Many atimes for some motion prolems, free-body diagrams has to be drawn many times so to have enough equations to solve for the unknowns. This is not the same with energy conservation principles.

2. In situations where we need to find the internal forces acting on an object, we can't truly solve such problems using free-body diagram as it captures external forces. This is not the same with energy conservation principles.

Explanation:

Often times the ideal method to use in solving motion problem related questions are mostly debated.

Energy conservation principles applies to isolated systems are useful when object changes their positions in moving upward or downward converts its potential energy due to gravity for kinetic energy, or the other way round. When energy in a system or motion remains constant that is energy is neither created nor destroyed, it can therefore be easier to calculate other unknown paramters like in the motion problem velocity, distance bearing it in mind that energy can only change from one type to another.

On the other hand, free body diagram which is a visual representation of all the forces acting on an object including their directions has so many advantages in solving motion related problems which include finding relationship between force and motion in identifying the force acting on a body.

5 0
3 years ago
Which of the following would have more momentum than fiona, a 313kg hippo, running at 8m/s?
kap26 [50]
Let's calculate the momentum of Fiona, given by the product between its mass and its speed:
p=mv=(313 kg)(8 m/s)=2504 kg m/s

Now let's compare it with the momentum of the other animals:
a) the mass of the sea turtle is missing, so we cannot calculate its momentum.
b) the momentum of the dolphin is 
p=mv=(150 kg)(18 m/s)=2700 kg m/s
c) the momentum of the horse is
p=mv=(380 kg)(4 m/s)=1520 kg m/s
d) the momentum of the lion is
p=mv=(190 kg)(11 m/s)=2090 m/s

And we can see that the correct answer is b), because the momentum of the dolphin is greater than the momentum of Fiona.
5 0
3 years ago
As an object falls in a gravitational field, its speed increases. This is an
kow [346]
The answer is
D. Kinetic energy
3 0
4 years ago
Read 2 more answers
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