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3 years ago

How old is the planet? how old is the earliest evidence of life on earth? ?

Physics

1 answer:

kipiarov [429]3 years ago

8 0

The earth is about 4.5 billion years old with evidence of life about 3.8 billion years ago.

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Two blocks of the same mass but made of different material slide across a horizontal, rough surface and eventually come to rest.

Akimi4 [234]

Answer:

a. $\mathbf{F_{f_2} = 2 F_{f1}}$ , $\mathbf { since \ the \ force \ o f \ friction \ is \ represented \ as \ the \ slope \ for \ each \ of \ the \ two \ curves.}$

Explanation:

From the information given;

Using the work-energy theorem

ΔKE = W = $\mathbf{ F_f \times r}$

K = $\mathbf{ F_f \times r}$

∴

$\dfrac{K_1}{K_2} = \dfrac{F_{f1}}{F_{f2}} (\dfrac{r_1}{r_2})$

Since $K_1 = K_2$ and r_1 = 4, and r_2 = 2 (from the missing diagram which is attached below)

Then;

$1 = \dfrac{F_{f1}}{F_{f2}} (\dfrac{4 \ m}{2 \ m})$

$\mathbf{F_{f_2} = 2 F_{f1}}$

5 0

2 years ago

Which choice is the BEST source of PROTEIN?<br> 1 Meat<br> 2 Bread<br> 3 Rice<br> 4 Apples

Kryger [21]

Answer: It's 1 meat.

Explanation: Meat is a protein, bread and rice are grains, Apples are fruit!

Your welcome

8 0

2 years ago

Read 2 more answers

Would hurt if u have a baby?

Shkiper50 [21]

Answer:

yes it would.

Explanation:

7 0

3 years ago

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A satellite, orbiting the earth at the equator at an altitude of 400 km, has an antenna that can be modeled as a 1.76-m-long rod

ivann1987 [24]

Answer:

The inducerd emf is 1.08 V

Solution:

As per the question:

Altitude of the satellite, H = 400 km

Length of the antenna, l = 1.76 m

Magnetic field, B = $8.0\times 10^{- 5}\ T$

Now,

When a conducting rod moves in a uniform magnetic field linearly with velocity, v, then the potential difference due to its motion is given by:

$e = - l(vec{v}\times \vec{B})$

Here, velocity v is perpendicular to the rod

Thus

e = lvB (1)

For the orbital velocity of the satellite at an altitude, H:

$v = \sqrt{\frac{Gm_{E}}{R_{E}} + H}$

where

G = Gravitational constant

$m_{e} = 5.972\times 10^{24}\ kg$ = mass of earth

$R_{E} = 6371\ km$ = radius of earth

$v = \sqrt{\frac{6.67\times 10^{- 11}\times 5.972\times 10^{24}}{6371\times 1000 + 400\times 1000} = 7670.018\ m/s$

Using this value value in eqn (1):

$e = 1.76\times 7670.018\times 8.0\times 10^{- 5} = 1.08\ V$

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3 years ago

A dog has a mass of 60kg and an acceleration of 2m/s/s. What is the force of the dog?

attashe74 [19]

Answer:

120 N

Explanation:

F=ma therefore 60kg times 2m/s^2 is 120 N

8 0

2 years ago

How old is the planet? ____________________ how old is the earliest evidence of life on earth? ____________________?

How old is the planet? how old is the earliest evidence of life on earth? ?