Answer:
5.5 to 7 Mohs
Explanation:
Glass ranks around 5.5 to 7 Mohs, but sapphire crystal has a hardness of 9 Mohs, making it only slightly less hard than diamond.
Answer: 5.5
Explanation:
Several hardness scales have been developed to catalog the materials (specifical minerals), being the Mohs scale the best known. This scale, proposed by the German geologist Friedrich Mohs in 1825, consists of a ratio of ten minerals numbered in increasing order by hardness, from least to greatest.
Find the direction of the sum of
these two vectors:
3.14 m,
30.0°
60.0°
2.71 m
The magnitude of the resultant vector is 4.14m and the direction is 50°.
What is the magnitude of the forces?The resultant magnitude of the vector is the sum of the algebraic forces acting at the point.
The magnitude of the resultant vector, F is calculated below:
[tex]F = \sqrt{3.14^{2} + 2.71^{2}} = 4.14m[/tex]
The direction is given below as follows:
[tex]x = tan^{-1} × \frac{3.14}{2.71} = 50[/tex]
Therefore, the magnitude of the resultant vector is 4.14m and the direction is 50°.
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A crate is being pushed at a constant velocity. What force are being used?
Answer:
Constant Speed
Explanation:
Answer:
Friction, inertia and constant speed
Explanation:
The friction and inertia create an equilibrium
A rural mail carrier leaves the post office and drives 22.0 km in a direction 35 degrees to the next town. She then drives in a direction 60.0 degrees for 47 km. What is her magnitude and displacement from the post office?
Answer:
D = 72.96 km, θ = 36.43º
Explanation:
This is a vector addition exercise, we are going to solve it by decomposing the displacements.
First displacement
cos 35 = x₁ / L
x₁ = L cos 35
cos 35 = y₁ / L
y₁ = L sin 35
x₁ = 22.0 cos 35 = 18.0 km
y₁ = 22 sin 35 = 12,619 km
Second displacement
cos 60 = x₂ / L
x₂ = L cos 60
x₂ = 47 cos 60 = 23.5 km
sin 60 = y₂ / L
y₂ = L sin 60
y₂ = 47 sin 60 = 40.70 m
In total displacement it is
x_total = x₁ + x₂
x_total = 18 + 40.7 = 58.7 km
y_total = y₁ + y₂
y_total = 12.629 +40.70
y_total = 53,329 km
Let's use the Pythagorean theorem
D = √(x_total² + y_total² )
D = √ (58.7² + 43,329²)
D = 72.96 km
For the direction we use trigonometry
tan θ = y_total / x_total
θ= tan-1 (43,329 / 58.7)
θ = 36.43º
What is the distance that an airplane traveling at 600 mph, moves during the time it takes to scan the instruments?, (Time is about 0.5 seconds, 5,280 ft/mi)
Answer:
d = 134.11 m
Explanation:
Speed of an airplane, = 600 mph
We need to find the distance moved in 0.5 s (to scan the instruments).
1 mph = 0.44704 m/s
It means,
600 mph = 268.22 m/s
Speed = distance/time
Distance, d = v t
d = 268.22 m/s × 0.5 s
d = 134.11 m
So, the distance moved by airplane is 134.11 m.
Object X travels across a horizontal surface and collides with object Y. The velocity as a function of time for object X and object Y before, during, and after the
collision is shown in the graph. Both objects have a mass of 2 kg. Which of the following correctly describes the momentum p of the system and the kinetic
energy K of the system?
Answer:
The correct option is;
(B) [tex]\underset{P}{\rightarrow}[/tex] is conserved, K Not conserved
Explanation:
From the diagram related to the question and from the question, we have;
m₁ = m₂ = 2 kg
v₁ = 4 m/s, v₂ = -2 m/s, v₃ = 1 m/s, therefore, we have;
The total initial momentum of the system = m₁ × v₁ + m₂ × v₂
m₁ (v₁ + v₂) = 2×(4 - 2) = 4 kg·m/s
The total final momentum of the system = m₁ × v₃ + m₂ × v₃ = 2 ×1 +2 ×1 = 4 kg·m/s
Given that the total initial momentum = The total final momentum, we have that the momentum, p, is conserved
The kinetic energy of the system before collision = 1/2×m₁×v₁² + 1/2×m₂×v₂²
∴ The kinetic energy of the system before collision = 1/2*2*(4)² + 1/2*2*(-2)² = 20 J
∴ The kinetic energy of the system after collision = 1/2×m₁×v₃² + 1/2×m₂×v₃²
1/2*2*(1)² + 1/2*2*(1)² = 2 J
The kinetic energy of the system before collision ≠ The kinetic energy of the system after collision
Therefore, the kinetic energy of the system is not conserved.
If the velocities of object X and object Y after collision is the same (inelastic collision), then only momentum is conserved but if the velocities of both objects after collision are different (elastic collision), then both momentum and kinetic energy are conserved.
According to principle of conservation of linear momentum, the total momentum before and after collision is conserved.
For inelastic collision, only momentum is conserved while kinetic energy is not conserved.
[tex]m_1u_1 \ + \ m_2u_2 = v(m_1 + m_2)[/tex]
[tex]\frac{1}{2} m_1u_1^2 \ + \frac{1}{2} m_2u_2^2 = \frac{1}{2}v^2(m_1+m_2)[/tex]
For elastic collision, both momentum and kinetic energy are conserved;
[tex]m_1u_1 \ + \ m_2u_2 =m_1v_1 \ + \ m_2v_2[/tex]
[tex]\frac{1}{2} m_1u_1^2 \ + \frac{1}{2} m_2u_2^2 = \frac{1}{2}m_1v_1^2 \ +\ \frac{1}{2}m_2v_2^2[/tex]
Thus, we can conclude that, if the velocities of object X and object Y after collision is the same (inelastic collision), then only momentum is conserved but if the velocities of both objects after collision are different (elastic collision), then both momentum and kinetic energy are conserved.
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Which formula equation shows a reversible reaction?
Answer:
If this is your question... the answer is C.
Explanation:
For edge:)
Answer:
C on edge2021
A golf ball with a mass of 45 g is rolling down a hill. At the bottom of the hill, its speed is 6 m/s. What is its GPE?
Answer:
GPE = 0 (when the golf is downhill)
GPE = 0.81 [J](when the golf is at the highest point of the hill)
Explanation:
In order to solve this problem, we must use the principle of energy conservation, which tells us that energy is transformed from kinetic energy to potential energy or vice versa.
We must define a reference energy point, where at this point the potential energy is zero. Let's take this point at the bottom of the hill.
At this point where the potential energy is zero, all the potential energy will have been transformed into kinetic energy, at this point the velocity will be maximum.
[tex]E_k=E_p\\where:\\E_{p}=m*g*h\\E_{k}=\frac{1}{2} *m*v^{2}[/tex]
where:
m = mass = 45 [g] = 0.045 [kg]
g = gravity acceleration = 9.81 {m/s²]
h = elevation [m]
v = velocity = 6 [m/s]
[tex]E_{k}=\frac{1}{2}*0.045*(6)^{2} \\E_{k}=E_{p}=0.81 [J][/tex]
GPE = 0 (when the golf is downhill)
GPE = 0.81 [J](when the golf is at the highest point of the hill)
PLEASE HELP ME!!
If the refractive index of water is 1.33, then its critical angle is...
WILL MARK BRAINLIEST not like anyone answers these.. but i need the RIGHTT ANSWERR people say its A or its D idkk???? u guys confuse me but hereee
The microwave oven was invented in 1945 when some experiments with radar equipment failed and melted some nearby chocolate instead. The scientists realized there were other applications for this energy source. What is this an example of?
A) Creative thinking
B) Scientific method
C) Scientific law
D) Artistic ability
Answer:
B)
Explanation:
Scientific method- a method of procedure that has characterized natural science since the 17th century, consisting in systematic observation, measurement, and experiment, and the formulation, testing, and modification of hypotheses.
in this, the scientist had to test their theories to find a solution to their problem.
A roller coaster of mass 2000 kg is rolling down a track with an
instantaneous speed of 10 m/s. The roller coaster has a force of
unknown magnitude act on it, so now it is traveling at only 6
m/s. What was the work done on it?
Kinetic energy = (1/2) (mass) (speed)²
The coaster's original kinetic energy was
KE = (1/2) (2,000 kg) (10 m/s)²
KE = (1,000 kg) (100 m²/s²)
KE = 100,000 kg-m²/s²
old KE = 100,000 joules
After something slowed it down, its new kinetic energy is
KE = (1/2) (2,000 kg) (6 m/s)²
KE = (1,000 kg) (36 m²/s²)
KE = 36,000 kg-m²/s²
new KE = 36,000 joules
The coaster lost (100,000 - 36,000) = 64,000 joules of KE.
Energy is conserved. It can't evaporate, disappear, or be destroyed.
That 64,000 joules had to go somewhere.
Someone or something had to do 64,000 joules of work on it in order to slow it down.
The work done by the external force on the roller coaster is 64000 J.
How do you calculate the work done on the roller coaster?Given that the mass of The roller coaster is 2000 kg and its velocity is 10 m/s. The kinetic energy of the roller coaster is given below.
[tex]KE = \dfrac {1}{2}mv^2[/tex]
[tex]KE = \dfrac {1}{2}\times 2000\times (10)^2[/tex]
[tex]KE = 100000 \;\rm J[/tex]
Since the roller coaster has a force of unknown magnitude which decreases its speed to 6 m/s. For this decreased speed, the kinetic energy is given as below.
[tex]KE'= \dfrac {1}{2}mv'^2[/tex]
[tex]KE'= \dfrac {1}{2}\times 2000\times 6^2[/tex]
[tex]KE' = 36000\;\rm J[/tex]
The work done on the roller coaster is calculated by the change in the kinetic energy for both speeds.
Work Done = KE - KE'
Work = 100000 - 36000
Work = 64000 J
Hence we can conclude that the work done by the external force on the roller coaster is 64000 J.
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Is a stone in the ground example of newtons first law of motion?
Answer:
yes, a stone in the ground is a example of newtons first law of motion because it does change it position until an external force is applied.
(Newton’s first law states that, if a body is at rest or moving at a constant speed in a straight line, it will remain at rest or keep moving in a straight line at constant speed unless it is acted upon by a force. )
Explanation:
When learning a new exercise what is the first thing you should focus on?
A
how much weight you can lift
B
if your form is correct
Dc
how many sets you can complete
D
if you can get done first
Answer:
If your form is correct (b)
Answer:
The answer is B if your form is correct
1) what is viscosity?
Which statement BEST describes scientific theories? A. Scientific theories attempt to explain an entire group of related phenomena. B. Scientific theories are based on facts that describe natural events. C. Scientific theories describe natural events but do not explain them. D. Scientific theories are facts based on observations of events in the natural world.
I NEED ANSWERS FAST!!
Answer:
C
Explanation:
A theory does not have any proven facts about it, it is just a theory, so this would likely be the best option.
Answer:
A. Scientific theories attempt to explain an entire group of related phenomena.
Explanation:
The suns in the binary star system would be very far away, how does this
impact the size they would be in the sky?
answerb this please asap
the second one
Explanation:
it isn't really a product tho its a byproduct
How does the period affects the centripetal force?
The speed of a car will increase if the car’s
Answer:
moving at a fast pace
Explanation:
Which of the following is a force or motion that
is involved in the Moon orbiting Earth?
A. a force pulling the Moon toward the
center
B. a speed at right angles to the line from
the mass of the Moon to the center of
Earth
C. acceleration toward the center of Earth
D. all of the above
Answer: this answer is D. That's what I think it is
Explanation:
If a golf ball is dropped from the thirteenth floor of a building, ignoring air resistance, after falling for 7.00 seconds the speed of the ball will be?
Explanation:
We know that
V = U + at
Here, u is 0 and a is 9.8 which is acceleration due to gravity.
Thus,
V = 9.8 *7
V = 68.6 m/s
Match the term with each description:
1. Acid
2. Alkaline
3. pH
4. Ion
Answer choices:
A.) An atom or molecule that has a positive or negative charge
B.) A value from 0 to 14 that is used to specify how acidic or basic a compound is when it is
C.) A compound that increases the hydroxide ions (OH-) when it is dissolved in a solution
D.) A compound that increases hydrogen ions (H+) when it is dissolved in a solution
Answer:
An acid is a compound that increases hydrogen ions (H+) when it is dissolved in a solution.
all I got
What is the difference between zone coverage and man coverage, and how can the offense team read those coverages?
Answer:
zone coverage is about sensing what the offense is attempting to accomplish against the defense. Each defensive player reacts when the ball is in the air, whereas in man-to-man coverage, he simply plays the receiver.
Explanation:
Power describes the
a. rate
b. scale
of the work that is being done.
C. amount
d. direction
Please select the best answer from the choices provided
Ο Α
О В
Ос
OD
Power describes the rate of the work that is being done. The correct option is A.
What is power?
Power is defined as the rate at which work is done or the amount of work done per unit time. In other words, power describes how quickly work is being done or how fast energy is being transferred.
The unit of power is the watt (W), which is equal to one joule of work per second.
Power can be calculated by dividing the amount of work done by the time it takes to do that work, or by multiplying the force applied by the distance traveled and dividing by the time it takes to travel that distance.
For example, if a machine does 100 joules of work in 10 seconds, then the power of the machine is 10 watts, calculated as:
Power = Work / Time
Power = 100 J / 10 s
Power = 10 W
Therefore, power describes the rate or speed at which work is being done, and it is measured in watts.
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what is the dimension of permeance
Answer:
metric dimensions, i think
Explanation:
How are a concave lens and a convex lens alike? How are they different?
ANSWER
A convex lens acts a lot like a concave mirror. ... A concave lens acts a lot like a convex mirror. Both diverge parallel rays away from a focal point, have negative focal lengths, and form only virtual, smaller images.
when carbon and oxygen combine chemically, what is true about the mass of the product
Answer: Equal to the mass of the carbon plus the mass of the oxygen
Explanation:
PLEASE HELP!!!!
One cereal bar has a mass of 37g. what is the mass of 6 cereal bars? is that more than or less than 1kg. explain your answer
Answer:
6 cereal bars = 222g, which is much less than 1kg
Explanation:
plss answer quickly
will mark brainliest
What similarities and differences can you observe about the motion of the Earth and the motion of the Moon?
Answer:
Both the earth and the moon go through rotation.
Explanation:
The earth rotates when going around the sun and the moon rotates when circling the earth
3 A ball is thrown haizonatally
oft a 7m building at omis
A man wants to catch the
ball in a basket 1sm of the
ground How ker away from the
building should he stand with
the basket
?
Answer:
Explanation:
very far look this up in the search the answer is there
hi im learning about zodiac sign can u share urs and what are some things u like to do im a aquarius i play vollyball and sing tysm≅
Answer:
Im a capricorn ! UwU
Explanation:
And well I like to watch my shows
draw / do art
Listen to music
spend time with people I care about
And secretly sing ;>
Hope I could help . :3
Hope u have a amazing rest of your day / night ! <3
Sleepy~