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garri49 [273]
3 years ago
13

Edwin Hubble calculated the expansion rate of the universe. On what evidence did he base his calculation?

Physics
2 answers:
algol [13]3 years ago
7 0

Edwin Hubble calculated the expansion rate of the universe. The evidence that he base his calculation is the differences in redshift for galaxies. The answer is letter B. the red shift of galaxies was directly proportional to the distance of the galaxy from earth.  It means that bodies farther away from Earth were moving away faster. The Hubble’s constant is the ratio of distance to redshift equal to 170 kilometers per second per light year of distance.

Anni [7]3 years ago
7 0

Answer: B

Explanation:

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The rate at which light energy is radiated from a source is measured in which of the following units?
romanna [79]
Answer is Option C Lumen.It is also known as luminous energy. 
8 0
3 years ago
Kevin jumps straight up in the air to a height of 1 meter.At the top of his jump, he has potential energy of 1,000 joules.Answer
Llana [10]
Gravitational potential energy can be given by the equation
PE = mgh
where m is the mass,
g is the gravitational constant 9.81 or 10 depending on rounding
and h is the height

well weight is a force equiavlent to
W= m*g

so comparing that to the potential energy equation, divide the potential energy by the height and you will get weight in Newtons


3 0
3 years ago
When pushed with the same amount of force a ross a desk which toy car would most likely travel the fastest A car weighing 25 gra
Arada [10]

Answer:

A car weighing 15 grams

Explanation:

According to the equation that shows the relationship between mass (m), force (F), and acceleration (a) i.e. F = ma, it can be seen that with a constant force, the mass is inversely proportional to the acceleration.

This means that an increase in mass of an object denotes a decrease in acceleration of that object and vice versa. Hence, according to this question, when pushed with the same amount of force, a car with the least mass will move faster. This car is the car weighing 15grams.

3 0
3 years ago
The energy band gap of GaAs is 1.4eV. calculate the optimum wavelength of light for photovoltaic generation in a GaAs solar cell
Viktor [21]

Answer:

λ = 8.88 x 10⁻⁷ m = 888 nm

Explanation:

The energy band gap is given as:

Energy Gap = E = 1.4 eV

Converting this to Joules (J)

E = (1.4 eV)(1.6 x 10⁻¹⁹ J/1 eV)

E = 2.24 x 10⁻¹⁹ J

The energy required for photovoltaic generation is given as:

E = hc/λ

where,

h = Plank's Constant = 6.63 x 10⁻³⁴ J.s

c = speed of light = 3 x 10⁸ m/s

λ = wavelength of light = ?

Therefore,

2.24 x 10⁻¹⁹ J = (6.63 x 10⁻³⁴ J.s)(3 x 10⁸ m/s)/λ

λ = (6.63 x 10⁻³⁴ J.s)(3 x 10⁸ m/s)/(2.24 x 10⁻¹⁹ J)

<u>λ = 8.88 x 10⁻⁷ m = 888 nm</u>

7 0
3 years ago
A child riding a bicycle at 5 meters per seconds accelerates at 2.0 meters per second for 4.0 seconds. What is the child's speed
slega [8]

Explanation:

Using Kinematics,

We have v = u + at.

=> v = (5m/s) + (2.0m/s²)(4.0s)

=> v = 13m/s.

Hence the child's speed is now 13m/s.

5 0
3 years ago
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