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3 years ago

Earth's age is closest to _____ years

2 answers:

8 0

<span>Since the planet Earth doesn't have a birth certificate to record its formation, scientists have spent hundreds of years struggling to determine the age of the planet. By dating the rocks in the ever-changing crust, as well as neighbors such as the moon and visiting meteorites, scientists have calculated that Earth is 4.54 billion years old, with an error range of 50 million years.
Hope this helps</span>

maksim [4K]3 years ago

6 0

Answer:

The Correct answer is D

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Recall specific heat of water is 4186 j/kg/C. Find the specific heat of sample.

Paraphin [41]

Answer:

Shown by explanation;

Explanation:

The heat of the sample = mass ×specific heat capacity of the sample × temperature change(∆T)

Assumption;I assume the mass of the samples are : 109g and 192g

∆T= 30.1-21=8.9°c.

The heat of the samples are for 109g are:

0.109 × 4186 × 8.9 =4060.84J

For 0.192g are;

∆T= 67-30.1-=36.9°c

0.192 × 4186×36.9=29656.97J

5 0

3 years ago

An electron and a proton are each placed at rest in an electric field of 500 N/C. Calculate the speed (and indicate the directio

Bumek [7]

Answer:

For proton: 2592 m/s In the same direction of electric field.

For electron: 4752000 m/s In the opposite direction of electric field.

Explanation:

E = 500 N/C, t = 54 ns = 54 x 10^-9 s,

Acceleration = Force /mass

Acceleration of proton, ap = q E / mp

ap = (1.6 x 10^-19 x 500) / (1.67 x 10^-27) = 4.8 x 10^10 m/s^2

Acceleration of electron, ae = q E / me

ae = (1.6 x 10^-19 x 500) / (9.1 x 10^-31) = 8.8 x 10^13 m/s^2

For proton:

u = 0, ap = 4.8 x 10^10 m/s^2, t = 54 x 10^-9 s

use first equation of motion

v = u + at

vp = 0 + 4.8 x 10^10 x 54 x 10^-9 = 2592 m/s In the same direction of electric field.

For electron:

u = 0, ae = 8.8 x 10^13 m/s^2, t = 54 x 10^-9 s

use first equation of motion

v = u + at

vp = 0 + 8.8 x 10^13 x 54 x 10^-9 = 4752000 m/s In the opposite direction of electric field.

6 0

3 years ago

Two objects attract each other gravitationally. If the distance between their centers decreases by a factor of 2, how does the g

kramer

Answer:

The gravitational force between them increases by a factor of 4

Explanation:

Gravitational force is a force of attraction between two objects with masses M and m which are separated by a distance R. It is given mathematically as:

Fg = GMm/R²

Where G = Gravitational constant.

If the distance between their centers, R, decreases by a factor of 2, then it means the new distance between their centers is:

r = R/2

Hence,the gravitational force becomes:

Fg = GMm/r²

Fg = GMm/(R/2)²

Fg = GMm/(R²/4)

Fg = 4GMm/R²

Hence,the gravitational force increases by a factor of 4.

6 0

3 years ago

To escape from a horrible fire, two people are forced to jump from the third story of a burning building onto solid concrete. Wh

erica [24]

The bouncing person because the bounce helped him survive

8 0

3 years ago

You can keep a 1kg apple from falling to the ground by placing it on a table. What reaction force is resisting the force of the

Gnom [1K]

The equilibrium condition allows finding the correct answer for the force that is resisting the weight of the apple is:

3. Normal force

Newton's second law gives the relationship between <em>force, mass</em> and acceleration of bodies, in the special case that the acceleration is is called the equilibrium condition.

∑ F = 0

Where F is the external force.

The free body diagram is a diagram of the forces on bodies without the details of the shape of the body, in the attached we can see a scheme of the forces.

Let's write the equilibrium condition for the apple

N - W = 0

N = W

We can see that the only forces acting on the apple are its weights and reaction from the table called Normal.

Let's analyze the different answers:

1. False. The apple is not moving therefore the resistance is zero

2. False. The apple is not moving so friction it with the table is

3. True. The free-body diagram shows that the normal and the weight are equal

4. False. There is nothing to pull the apple so there is no tension

5. False. Gravity is the weight of the apple that is applied to the table, not from the table to the apple.

In conclusion using the equilibrium condition we can find the correct result for the force that is resisting the weight of the apple is:

3. Normal force

Learn more here: brainly.com/question/2872207

8 0

3 years ago