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3 years ago

14

Based on The MOHS hardness Scale, which mineral could be scratched by a penny but not by a fingernail

1 answer:

melomori [17]3 years ago

6 0

The correct answer is B. Calcite

Explanation:

Mohs hardness scale indicates the hardness of minerals using a scale from 1 to 10 as well as defining the objects or tools that can be used to scratch the minerals. These two features of minerals are shown in the table of the image. About this, it is shown gypsum and talc can be scratched by just a fingernail, considering minerals with a hardness of 2.5 or below can be scratched by a fingernail. In the case of calcite that has a hardness of 3, this cannot be scratched by a fingernail, but it can be scratched by a penny, which works for minerals with a hardness of 3.5 or below. Thus, the correct answer is Calcite.

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Many of the whales in the ocean rely upon tiny marine organisms, called plankton, for food. If all of the plankton suddenly died

exis [7]

Answer:

I believe the answer to be B.

Explanation:

Without food, the whales would die.

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3 years ago

A black lift of amber is placed in water and a laser beam travels from the water through the amber. The angle of incidence is 35

horsena [70]

Answer:

Explanation:

refractive index of ember = sin of angle of incidence / sin of angle of refraction

= sin 35 / sin24

= .5735 / .4067

= 1.41

This is refractive index of ember with respect to water

refractive index of ember with respect to water

= wμe = μe / μw

μe = wμe x μw

= 1.33 x 1.41

= 1.87

refractive index of ember with respect to air = 1.87 .

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3 years ago

you are piloting a small plane and you want to reach an airport 450 km due south in 3.0 h a wind is blowing from the west 50.0 k

alex41 [277]

Answer:

You should choose airspeed 158.11 km/h at 18.4° west of south

Explanation:

The distance to the air port is 450 km due to south

You should to reach the airport in 3 hours

→ Velocity = distance ÷ time

→ Distance = 450 km , time = 3 hours

→ The velocity of your plane = 450 ÷ 3 = 150 km/h due to south

A wind is blowing from west 50 km/h

We need to know what heading and airspeed you should choose to

reach your destination

At first we must find the resultant velocity of your plane and the wind

The south and west are perpendicular, then the resultant velocity is

→ $v_{R}=\sqrt{(v_{p})^{2}+(v_{w})^{2}}$

→ $v_{p}=150$ km/h , $v_{w}=50$ km/h

→ $v_{R}=\sqrt{(150)^{2}+(50)^{2}}=158.11$ km/h

To cancel the velocity of the wind, the pilot should maintain the velocity

of the plane at 158.11 km/h

The direction of the velocity is the angle between the resultant velocity

and the vertical (south)

→ The direction of the velocity is $tan^{-1}\frac{50}{150}=18.4$ °

The direction of the velocity is 18.4° west of south

<em>You should choose airspeed 158.11 km/h at 18.4° west of south</em>

8 0

3 years ago

The force of gravity on Jupiter is much stronger than the force of gravity on earth what is the answer?

Pachacha [2.7K]

This would be true. On Jupiter you would weigh 234 pounds if you were 100 pounds on Earth.

7 0

3 years ago

Read 2 more answers

An optical fiber is 1.0 meter long and has a diameter of 20 μm. Its ends are perpendicular to its axis. Its index of refraction

scoundrel [369]

Complete Question

The complete question is shown on the first uploaded image

Answer:

The answer is a

Explanation:

The explanation is shown on the second uploaded image

6 0

3 years ago