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DiKsa [7]
3 years ago
9

Why do scientists believe that dark matter exists even though it cannot be seen?

Physics
1 answer:
poizon [28]3 years ago
3 0
Because although they cannot see it, they can see it's influence on objects that can be seen, and it's effects.
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At its maximum speed, a typical snail moves about 4.0 m in 5.0 min.
stiv31 [10]

Answer:

Explanation:

Given

Distance = 4.0m

Time = 5.0 mins = 300secs

Required

Average speed

Average speed = Distance/Time

Average speed = 4.0/300

Average speed = 0.01333m/secs

Hence the average speed of the snail is 0.01333m/s

6 0
3 years ago
Which of the following diagrams shows the path of deep water currents in the ocean?
Whitepunk [10]
I hope this helps. ^-^

6 0
3 years ago
A student attaches a block to a vertical spring so that the block-spring system will oscillate if the block-spring system is rel
vodka [1.7K]

Answer:

Time period of the motion will remain the same while the amplitude of the motion will change

Explanation:

As we know that time period of oscillation of spring block system is given as

T= 2\pi\sqrt{\frac{M}{k}}

now we know that

M = mass of the object

k = spring constant

So here we know that the time period is independent of the gravity

while the maximum displacement of the spring from its mean position will depends on the gravity as

mg = kx

x = \frac{mg}{k}

so we can say that

Time period of the motion will remain the same while the amplitude of the motion will change

4 0
3 years ago
The area around a charged object that can exert a force on other charges objects is an electric_____.
lisov135 [29]
Electric force... Hope this helps

6 0
3 years ago
Read 2 more answers
In an experiment you measure a first-order red line for Hydrogen at an angle difference of ΔΘ = 22.78o. The diffraction grating
azamat

Answer:

a) wavelength = 656.3 nm

b)  the value of Rydberg's constant for this measurement is 1.097 × 10⁷ m⁻¹

Explanation:

Given that;

angle of diffraction Θₓ = 22.78°

incident angle Θ₁ = 0

slit separation d  = 5900 lines per cm = 1/5900 cm = 10⁻²/5900 m = 0.01/5900 m

order of diffraction n = 1

wavelength λ = ?

to find the wavelength, we use the expression

λ = d (sinΘ₁ + sinΘₓ) / n

To find the wavelength λ;

λ = 0.01/5900 × (sin0 + sin22.78° )

λ = 6.5626 × 10⁻⁷ m

λ = 656.3 x 10⁻⁹ m

∴ λ = 656.3 nm

b)

According Balnur's  series spectral lines; n₁ = 3, n₂ = 2 and

λ = R [ 1/n₂² - 1/n₁²]

where  R is Rydberg's constant

from λ = R [ 1/n₂² - 1/n₁²]

R = 1/λ [n₂²n₁² / n₁² - n₂²]

R = 10⁹/ 656.3 [ 9 × 4 / 9 - 4 ]

R = 1.097 × 10⁷ m⁻¹

Therefore the value of Rydberg's constant for this measurement is 1.097 × 10⁷ m⁻¹

4 0
3 years ago
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