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
Hoochie [10]
3 years ago
12

What is dark energy and what evidence do astronomers have that it is an important component of the universe?

Physics
1 answer:
PSYCHO15rus [73]3 years ago
8 0

Answer:

The existance of dark energy was suggested to help explain measurements, using Type Ia supernovae as distance indicators, that the expansion of the universe is speeding up and its acceleration requires a source of energy. Scientists suggested that It may be a new form of energy for which there is not yet a theoretical explanation. quantum mechanics predict that it may be the vacuum energy associated with "empty" space itself.

You might be interested in
What would it be like to walk on Venus?
maria [59]

it will be very hot so that causes nobody to walk on venus because its the hottest outer planet.

hope I helped :)

3 0
3 years ago
The downsprue leading into the runner of a certain mold has a length of 175 mm. The cross-sectional area at the base of the spru
adoni [48]

Answer:

(a) Velocity at bottom is 1.85 m/s

(b) Volume flow rate is 7.4 x 10⁻⁴ m³/s.

(c) The time required to fill the mold is 1.35 s.

Explanation:

(a)

Applying Bernoulli's Equation on both ends of the down sprue, with the assumptions that every point is at atmospheric pressure and the liquid metal at the pouring basin is at zero velocity. The equation then becomes:

V = √2gh

where,

V = velocity at bottom of down sprue

h = height of down sprue = 175 mm = 0.175 m

V = √2(9.8 m/s²)(0.175 m)

<u>V = 1.85 m/s</u>

<u></u>

(b)

The volume flow rate is given as:

Volume Flow Rate = (V)(A)

where,

V = velocity at bottom = 1.85 m/s

A = Area of bottom = 400 mm² = 0.0004 m²

Therefore,

Volume Flow Rate = (1.85 m/s)(0.0004 m²)

<u>Volume Flow Rate = 7.4 x 10⁻⁴ m³/s = 740 cm³/s</u>

(c)

The time required to fill the cavity is given as:

Volume Flow Rate = V/t

where,

V = Volume of mold Cavity = 0.001 m³

t = time required to fill the cavity = ?

Therefore,

t = V/Volume Flow Rate

t = 0.001 m³/7.4 x 10⁻⁴ m³/s

<u>t = 1.35 s</u>

<u></u>

5 0
3 years ago
For this situation to demonstrate a balanced force, how much force must Omar apply? (In the picture, Sam is pushing a box to the
11111nata11111 [884]
The answers 10N as it equals it out
3 0
3 years ago
Read 2 more answers
A hotel elevator ascends 200m with maximum speed of 5m/s. Its acceleration and deceleration both have a magnitude of 1.0m/s2. Pa
ValentinkaMS [17]

Answer:

45 s .

Explanation:

The accelerator will first accelerate , then move with uniform velocity and at last it will decelerate to rest .

displacement s = ?

acceleration a = 1 m /s²

Final speed v = 5 m/s

initial speed u = 0

v² = u² + 2as

5² = 0 + 2 x 1 x s

s = 12.5  m

B)  Let time of acceleration or deceleration be t

v = u + a t

5 = 0 + 1 t

t = 5 s

Similarly displacement during deceleration = 12.5 m

Total distance during uniform motion = 200 - ( 12.5 + 12.5 ) =  175 m .

velocity of uniform motion = 5 m /s

time during which there was uniform velocity = 175 / 5 = 35 s

Total time = 5 + 35 + 5 = 45 s .

4 0
2 years ago
what is the valure of work done on an objectwhen a 50newton force moves it 15 metrs in thesame dirction as the force
Snowcat [4.5K]
50 *15=750
work is force time distance times angle between both vectors 
here the angle is 0.
5 0
3 years ago
Other questions:
  • List important agents,or causes of erosion
    9·2 answers
  • Which characteristics of Earth’s orbit are in agreement with Kepler’s second law? Check all that apply.
    14·2 answers
  • What is an example of volume ​
    9·2 answers
  • Which planet has a ring system made of mostly water ice?
    7·2 answers
  • A motorcycle rides on the vertical walls around the perimeter of a large circular room. The friction coefficient between the mot
    6·1 answer
  • The speed or celerity of deep-water waves... A. increases with increasing water depth B. increases as water becomes blue in colo
    14·1 answer
  • Someone help me I will mark brainless it’s 2 questions .
    12·1 answer
  • If a person attempts to read their e-mail while they are riding the bus, they are _______.
    7·1 answer
  • What percentage of an iron anchor’s weight will be supported by buoyant force when submerged in salt water?
    15·1 answer
  • State Newton's second law of motion in terms of momentum<br>​
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!