1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
son4ous [18]
3 years ago
11

What holds a galaxy together?

Physics
2 answers:
Tju [1.3M]3 years ago
8 0
Gravity is what holds a galaxy together
ohaa [14]3 years ago
6 0
Gravity holds it together
You might be interested in
A 2kg object is moving horizontally with a speed of 4 m/s. How much net force is required to keep the object moving at this spee
Elza [17]
We can solve this problem using the force equation.

Force = Mass * Acceleration

2kg * 4m/s = 8 N

The net force required to keep the object moving at this speed and in this direction is 8 N.


8 0
3 years ago
Read 2 more answers
A train going 14m/s moves 250 m while accelerating to a stop. What is the train’s deceleration?
Elanso [62]

Answer:

-0.056 is the deceleration

6 0
3 years ago
What can change shape and volume? PLz help :)
Rasek [7]
Gas has no certain shape However, its Volume can change with Differences in Heat and Pressure.
6 0
3 years ago
Read 2 more answers
What is the wavelength, in nm, of a photon with energy
lara31 [8.8K]

Answer:

(a)  λ = 4136 nm → infrared

(b) λ = 413.6 nm → visible light

(c) λ = 41.36 nm → ultraviolet

Explanation:

The wavelength of infrared is on the range of 700 nm to 1000000 nm

The wavelength of visible light is between 400 nm and 700 nm

The wavelength of ultraviolet ray on the range of 10 nm to 400 nm

The wavelength of photon is given by;

E = hf

f is the frequency of the wave = c / λ

E = h\frac{c}{\lambda}\\\\ \lambda = \frac{hc}{E}

Where;

c is the speed of light = 3 x 10⁸ m/s

h is Planck's constant = 6.626 x 10⁻³⁴ J/s

(a) 0.3 eV = 0.3 x 1.602 x 10⁻¹⁹ J

\lambda = \frac{(6.626 * 10^{-34})(3*10^8)}{(0.3)*(1.602*10^{-19})}\\\\\lambda = 4.136 *10^{-6} \ m

λ = 4136 x 10⁻⁹ m

λ = 4136 nm → infrared

(b) 3.0 eV

\lambda = \frac{(6.626 * 10^{-34})(3*10^8)}{(3)*(1.602*10^{-19})}\\\\\lambda = 4.136 *10^{-7} \ m

λ = 413.6 x 10⁻⁹ m

λ = 413.6 nm →visible light

(c) 30 eV

\lambda = \frac{(6.626 * 10^{-34})(3*10^8)}{(30)*(1.602*10^{-19})}\\\\\lambda = 4.136 *10^{-8} \ m

λ = 41.36 x 10⁻⁹ m

λ = 41.36 nm →ultraviolet

5 0
3 years ago
Suppose a police officer is 1/2 mile south of an intersection, driving north towards the intersection at 30 mph. at the same tim
aleksandr82 [10.1K]

In triangle ABC , using Pythagorean theorem

BC = sqrt(AB² + AC²)

r = sqrt(y² + x²)                                eq-1

taking derivative both side relative to "t"

dr/dt = (1/(2 sqrt(y² + x²) ) ) (2 y (dy/dt) + 2 x (dx/dt))

dr/dt = (1/(2 sqrt(0.5² + 0.5²) ) ) (2 (0.5) (dy/dt) + 2 (0.5) (dx/dt))

dr/dt = (1/(2 sqrt(0.5² + 0.5²) ) ) ( v₁ + v₂)

15= (1/(2 sqrt(0.5² + 0.5²) ) ) ( - 30 + v₂)

v₂ = 51.2 m/s

3 0
3 years ago
Read 2 more answers
Other questions:
  • Will give thanks!!! 38 pts
    12·1 answer
  • Which type of bond shows two or more atoms sharing electrons?
    10·1 answer
  • A meter stick balances at the 50.0-cm mark. If a mass of 50.0 g is placed at the 90.0-cm mark, the stick balances at the 61.3-cm
    13·2 answers
  • The 2004 Indian Ocean tsunami was caused by a shift in two plates that pushed one section of the sea floor under another section
    9·2 answers
  • A farmer places unhatched chicken eggs under a heat lamp. How does the radiation help the eggs?
    13·2 answers
  • How do you do this question?
    13·1 answer
  • I apologise for asking too many questions. its because its a surprise test I didnt study. Thank you to the people who helped me.
    7·1 answer
  • A 1kg sphere rotates in a circular path of radius 0.2m from rest and it reaches an angular speed of 20rad/sec in 10 second calcu
    11·1 answer
  • A 50-ω resistor is connected to a 9.0 V battery. How much thermal energy is produced in 7.5 minutes?
    5·1 answer
  • Why is it so difficult for astronomers to see new stars in the process of birth?
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!