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3 years ago

The early earth was much cooler than it is today. a. True b. False

1 answer:

Pie3 years ago

5 0

This statement is true. Early earth was much cooler than it is today.

This is because the pollution as well as the population number was very small compared to nowadays population and pollution.
The pollution mainly is causing a decay in the ozone layer which protects the earth from uv rays. Thus, more of these rays enter the atmosphere and increase the temperature.
The increase in population along with the decrease in green areas leads to the increase in the percentage of carbon dioxide in the atmosphere, which again leads to an increase in the temperature.

You might be interested in

The ______ and _______ are used to calculate magnitude and direction of a resultant vector.

S_A_V [24]

Here are the correct answers that would complete the given statement above. The vector quantity and the vector arrow are used to calculate magnitude and direction of a resultant vector. Vector quantity has both magnitude and direction, whereas vector arrow represents the magnitude of a quantity and the direction represents the direction of that quantity. Hope this is the answer that you are looking for.

3 0

3 years ago

What happens when a sound wave passes from oil into air? A. the sound wave slows down and bounces back B. the sound wave slows d

Jlenok [28]

Oil is optically denser than water. When sound/light goes from optically denser medium to optically rarer medium, their velocity increase and they moves away for normal.

<h3>Appropriate Answer:</h3>

The sound wave speeds up and bends

$\Large{ \underline{ \boxed{ \pink{ \bf{Option \: (D)}}}}}$

As, In optics we learnt that light undergoes refraction when travels from medium of different densities. Similarly, Sound also follows the law of refraction.

It is due to the change of speed of water in different mediums, This makes it speed up or down depending upon the medium and their densities.

━━━━━━━━━━━━━━━━━━━━

6 0

3 years ago

A speedboat increases its speed from 14.5 m/s to 29.3 m/s in a distance of 172 m.

dalvyx [7]

Answer:

a. Acceleration, a = 1.88 m/s²

b. Time, t = 7.87 seconds.

Explanation:

Given the following data;

Initial velocity, U = 14.5m/s

Final velocity, V = 29.3m/s

Distance, S = 172m

a. To find the acceleration of the speedboat;

We would use the third equation of motion;

V² = U² + 2aS

Substituting into the formula

29.3² = 14.5² + 2a*172

858.49 = 210.25 + 344a

344a = 858.49 - 210.25

344a = 648.24

a = 648.24/344

Acceleration, a = 1.88 m/s²

b. To find the time;

We would use the first equation of motion;

V = U + at

29.3 = 14.5 + 1.88t

1.88t = 29.3 - 14.5

1.88t = 14.8

Time, t = 14.8/1.88

Time, t = 7.87 seconds.

6 0

3 years ago

Susan's 10.0kg baby brother Paul sits on a mat. Susan pulls the mat across the floor using a rope that is angled 30? above the f

elena-s [515]

Answer:

The speed after being pulled is 2.4123m/s

Explanation:

The work realize by the tension and the friction is equal to the change in the kinetic energy, so:

$W_T+W_F=K_f-K_i$ (1)

Where:

$W_T=T*x*cos(0)=32N*3.2m*cos(30)=88.6810J\\W_F=F_r*x*cos(180)=-0.190*mg*x =-0.190*10kg*9.8m/s^{2}*3.2m=59.584J\\ K_i=0\\K_f=\frac{1}{2}*m*v_f^{2}=5v_f^{2}$

Because the work made by any force is equal to the multiplication of the force, the displacement and the cosine of the angle between them.

Additionally, the kinetic energy is equal to $\frac{1}{2}mv^{2}$ , so if the initial velocity $v_i$ is equal to zero, the initial kinetic energy $K_i$ is equal to zero.

Then, replacing the values on the equation and solving for $v_f$ , we get:

$W_T+W_F=K_f-K_i\\88.6810-59.5840=5v_f^{2}\\29.097=5v_f^{2}$

$\frac{29.097}{5}=v_f^{2}\\\sqrt{5.8194}=v_f\\2.4123=v_f$

So, the speed after being pulled 3.2m is 2.4123 m/s

8 0

3 years ago

How does the carbon rod of a cell beomes a positive terminal?

ivann1987 [24]

Answer:

In the middle of a dry cell, is a rod made of carbon. Around the carbon rod is a chemical paste. At the same time, the carbon rod becomes positively charged. When this happens, electrical current flows out of the cell when a conductor is attached between the cell's positive and negative terminals.

7 0

3 years ago