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3 years ago

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.

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Suppose the designers of the water slide want to adjust the height h above the water so that riders land twice as far away from

Nitella [24]

Answer:

option C

Explanation:

given,

Range is doubled

for range to be doubled height should become 4 times.

formula to calculate the horizontal range

R = v T_{flight}

using equation of motion

$s = u t + \dfrac{1}{2}at^2$

$t=\sqrt{\dfrac{2s}{g}}$

now,

$R = v\sqrt{\dfrac{2h}{g}}$

where, h is the height of the

Assuming the height be equal to 0.6 m

to calculate the new height

$h_{new}= 4 h$

$h_{new}= 4\times 0.6$

$h_{new}= 2.4\ m$

hence, the correct answer is option C

4 0

3 years ago

Yolanda has decided she is going to be a nurse. What is the next step she should take to make her career goals a reality? a. Cre

andrew11 [14]

The correct answer is option D

When someone decides to do something then he or she must prepare themselves according to the career they choose.

When Yolanda has decided to be a nurse then she must create an individual career plan and start working on it.

A goal oriented person only works in the area of their goal and accomplishes it.

8 0

3 years ago

Read 3 more answers

What is the velocity of a car that travels from mile marker 32 on I-10 to mile marker 312 on I-10 in a time of 2 hours and 45 mi

Dimas [21]

Answer:

101.81818 MPH

Explanation:

8 0

3 years ago

The Hubble Space Telescope (HST) orbits 569 km above Earth’s surface. If HST has a tangential speed of 7,750 m/s, how long is HS

deff fn [24]

Answer: 5,640 s (94 minutes)

Explanation:

the tangential speed of the HST is given by

$v=\frac{2\pi r}{T}$ (1)

where

$2\pi r$ is the length of the orbit

r is the radius of the orbit

T is the orbital period

In our problem, we know the tangential speed: $v=7,750 m/s$ . The radius of the orbit is the sum of the Earth's radius and the distance of the HST above Earth's surface: