Which if these events happens first in earths polar regions

Friction is a force in which two objects __________.

balu736 [363]

The answer should be C) Slide against each other.

7 0

2 years ago

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if researchers hit a sheet of metal with a yellow light and nothing happens, what color should the try next?

Nataliya [291]

The photoelectric emission is possible if the wavelength of the incident light is less than that of yellow light

3 0

3 years ago

The first car has twice the mass of a second car, but only half as much kinetic energy. When both cars increase their speed by 9

kirill [66]

Answer:

Speed of the car 1 = $V_1=8.98m/s$

Speed of the car 2 = $V_2=17.96m/s$

Explanation:

Given:

Mass of the car 1 , M₁ = Twice the mass of car 2(M₂)

mathematically,

M₁ = 2M₂

Kinetic Energy of the car 1 = Half the kinetic energy of the car 2

KE₁ = 0.5 KE₂

Now, the kinetic energy for a body is given as

$KE =\frac{1}{2}mv^2$

where,

m = mass of the body

v = velocity of the body

thus,

$\frac{1}{2}M_1V_1^2=0.5\times \frac{1}{2}M_2V_2^2$

or

$\frac{1}{2}2M_2V_1^2=0.5\times \frac{1}{2}M_2V_2^2$

or

$2M_2V_1^2=0.5\times M_2V_2^2$

or

$2V_1^2=0.5\times V_2^2$

or

$4V_1^2= V_2^2$

or

$2V_1= V_2$ .................(1)

also,

$\frac{1}{2}M_1(V_1+9.0)^2=\frac{1}{2}M_2(V_2+9.0)^2$

or

$\frac{1}{2}2M_2(V_1+9.0)^2=\frac{1}{2}M_2(2V_1+9.0)^2$

or

$2(V_1+9.0)^2=(2V_1+9.0)^2$

or

$\sqrt{2}(V_1+9.0)=(2V_1+9.0)$

or

$(\sqrt{2}V_1+ \sqrt{2}\times 9.0)=(2V_1+9.0)$

or

$(\sqrt{2}V_1+ 12.72)=(2V_1+9.0)$

or

$(2V_1-\sqrt{2}V_1)=(12.72-9.0)$

or

$(0.404V_1)=(3.72)$

or

$V_1=8.98m/s$

and, from equation (1)

$V_2=2\times 8.98m/s = 17.96m/s$

Hence,

Speed of car 1 = $V_1=8.98m/s$

Speed of car 2 = $V_2=17.96m/s$

8 0

2 years ago

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As air is heated, the particles speed up and spread out (becoming less dense). Hot air balloon pilots can change the balloon’s a

Jobisdone [24]

Answer:

Turn the heater on

Explanation:

There are two main forces involved in a balloon flight

The downward force is the total weight of the balloon: the air it contains, the gas bag, the basket, the passengers, etc.

The upward force is the weight of the of the air the balloon displaces.

During level flight ,

buoyant force = weight of displaced air - total weight of balloon

If you increase the temperature of the air in the bag, the air molecules spread out and leave through the bottom of the bag.

The balloon still has the same volume, so the weight of displaced outside air stays the same.

However, the balloon has lost some hot inside air, so its total weight decreases.

The upward force is greater than the downward force, so the balloon rises.

3 0

3 years ago

How much heat is required to warm 122 g of water by 23.0 c?

GaryK [48]

4 0

3 years ago

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