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
-BARSIC- [3]
3 years ago
13

What led astronomers to believe in the existence of dark matter?

Physics
1 answer:
Tju [1.3M]3 years ago
3 0
It’s either C or D. let me know but I would do C!
You might be interested in
What is the input of energy for a device that provides 50 units of useful energy and has an efficiency of 0.55?
marshall27 [118]

If that's the case, then 

                          50 units = 0.55 x the input energy

Divide each side by  0.55 :       

                   50 units/0.55  =  the input energy =

                              <em> 90 and 10/11 units</em>


3 0
4 years ago
(1 point) A frictionless spring with a 6-kg mass can be held stretched 0.2 meters beyond its natural length by a force of 50 new
guapka [62]

Answer:

x(t) = 0.077cos(6.455t)

Explanation:

If the spring can be stretched 0.2 m by a force of 50 N, then the spring constant is:

k = 50 / 0.2 = 250 N/m

The equation of simple harmonic motion is as the following:

x(t) = Acos(\omega t - \phi)

where \omega = \sqrt{k/m} = \sqrt{250 / 6} = 6.455

We also know that the initial velocity is 0.5 m/s, which is also the maximum speed at the equilibrium:

v_{max} = A\omega

A = v_{max}/\omega = 0.5 / 6.455 = 0.077 m

\phi = 0 is the initial phase

Therefore, the position of the mass after t seconds is

x(t) = 0.077cos(6.455t)

6 0
3 years ago
Work out the current through an electric heater with a power of 1.38kW if it uses the 230V mains supply.
love history [14]

Answer:

I = 6 A

Explanation:

Given that,

Power of an electric heatr, P = 1.38 kW

The voltage of the mains supply, V = 230 V

We need to find the current through the heater. The electric power in terms of  voltage and current is given by :

P=V\times I\\\\I=\dfrac{P}{V}\\\\I=\dfrac{1.38\times 10^3}{230}\\\\I=6\ A

So, the current through an electric heater is 6 A.

5 0
3 years ago
If Joey ran 60 meters in 10 seconds, then his velocity is ________ m/s.
BabaBlast [244]

Answer:

6 m/s

Explanation:

6 0
4 years ago
Read 2 more answers
Which action can be explained by physics
Lunna [17]
Dropping two objects and seeing them hit the ground at the same time 
3 0
4 years ago
Read 2 more answers
Other questions:
  • The atmosphere is heated most by which of the following?
    5·1 answer
  • The impulse given to a ball with mass of 4 kg is 16 N s. If the ball starts from rest, what is its final velocity?
    13·1 answer
  • How did Dalton think atoms formed a new substance?
    10·1 answer
  • In 1993, Ileana Salvador of Italy walked 3.0 km in under 12.0 min. Suppose that during 115 m of her walk Salvador is observed to
    6·1 answer
  • Find the force. 10 points. Will give brainliest!
    6·2 answers
  • One may conceive light to spread successively, by spherical waves.
    10·2 answers
  • The strongest hurricane to hit the United States was a small storm. Why did it cause so much damage?
    10·2 answers
  • Can u please tell and explain
    15·1 answer
  • Sean is moving heavy furniture by sliding it across the floor. He puts a blanket underneath the furniture. Why dis this help him
    14·1 answer
  • A 45 g bug is hovering in the air. A gust of wind
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!