Answer:hardness
Explanation: I’m smart like dhet
Answer:
Luster
Explanation:
Hardness is very important for seperating rocks and minerals.
However, Luster is not as common, nor on many questions.
In 2014, physicists from FOM Foundation at the University of Amsterdam introduced a new hypothesis of how the Pyramids at Giza were built. The group of physicists suggestedthat ancient Egyptians wetted sand in an effort toreduce friction and then pulled the 3000 kg stoneblocks to their final resting place. 15 men couldmove a block at a rate of 0.5m/sby pulling a largerope angled at 30owith respect to the plane anda tension of 7,200 N.
Required:
a. What is net work done on block?
b. What is speed of blck after it moved .25m?
c. What is work done by block if kinetic friction coefficient is 0.3?
d. What is net work including friction?
Answer:
The correct answer is:
(a) 0
(b) 0.5 m/s
(c) 7740 N
(d) 0
Explanation:
The given values are:
mass,
m = 3000 kg
Tension,
T = 7,200 N
Angle,
= 30°
(a)
Even as the block speed becomes unchanged, the kinetic energy (KE) will adjust as well:
⇒ [tex]\Delta K =0[/tex]
By using the theorem of energy, the net work done will be:
⇒ [tex]\Delta K =0[/tex]
(b)
According to the question, After 0.25 m the block is moving with the constant speed
= 0.5 m/s.
(c)
The given kinetic friction coefficient is:
u = 0.3
The friction force will be:
= [tex]u(mg-Tsin30^{\circ})[/tex]
On substituting the values, we get,
= [tex]0.3[(3000\times 9.8)-(7200\times 0.5)][/tex]
= [tex]0.3[29400-3600][/tex]
= [tex]0.3\times 25800[/tex]
= [tex]7,740 \ N[/tex]
(d)
On including the friction,
The net work will be:
⇒ [tex]\Delta K=0[/tex]
Directions: Follow the instructions to go through the simulation. Respond to the questions and prompts in the orange boxes. Vocabulary: air track, approach velocity, conservation of energy, conservation of momentum, elasticity, kinetic energy, momentum, separation velocity, velocity Prior Knowledge Questions (Do these BEFORE using the Gizmo.) Imagine going to a bowling alley with a bowling ball and a ping pong ball. Why is a bowling ball better for knocking down pins than a ping pong ball?
Answer and Explanation: Momentum (Q) is defined as mass in motion, which means it relates mass of an object with its velocity:
Q = m.v
So, momentum only depends on mass of the object and the velocity it is moving.
Comparing bowling ball and ping pong ball, the first one has more mass than the second one. Therefore, a bowling pin will better knock down the pins than the ping pong ball.
A 2.00-kg ball is moving at 2.20 m/s toward the right. It collides elastically with a 4.00-kg ball that is initially at rest. 1) Calculate the final velocity of the 2.00-kg ball. (Express your answer to three significant figures.)
Answer:
The final velocity of the 2kg ball is 1.270 m/s
Explanation:
According to Newton's second and third laws of motion
Newton's second law state that "the rate of change of momentum is proportional to the applied force and takes place in the direction of that force".
Newton's third law state that "for every action, there must be an equal and opposite reaction".
The combinations of these two laws resulted in an elastic collision
Given that:
m1 = 2kg
u1 = 2.20m/s
m2 = 4.00kg
u2 = 0m/s
An Elastic collision is when kinetic energy before = kinetic energy after
E.K before = [tex]1/2mv^{2}[/tex]
E.K before = 1/2 * 2 * (2.20)^2
E.K = 1/2 * 2 * 4.84
E.K before = 4.84j
E.K after = 1/2 x (4 + 2)v^2
E.K after = 1/2(6v^2)
E.K after = 3v^2
Since E.K before = E.K after
4.84 = 3v^2
Divide through by 3
4.84/3 = 3v^2/3
1.6133 = v^2
[tex]V = \sqrt{1.6133} \\V = 1.270 m/s[/tex]
What happens to the energy of a rubber band when it is stretched?
how does temperature affect brownian motion
Answer: This (random) thermal motion of the particles due to the temperature is also called Brownian motion. ... The higher the temperature, the faster the diffusion will be, because the stronger the molecule movement and thus the “mixing”.
Explanation:
An experiment is designed to compare the differences in learning outcomes
between learning math from a video game and learning it from traditional
classroom activities. The experiment finds no difference between the two.
Which experiment method is important for controlling bias?
A. Developing a video game with subjects' input
B. Randomly assigning students to the two different groups
C. Asking the subjects which group they preferred to be in
D. Using classroom activities with researchers' input
Answer:
B. Randomly assigning students to the two different groups
Explanation:
The bias can be controlled by making use of the randomized block design where we divide the subject into subgroups also called blocks and randomly assign treatment conditions to each block.
In this case, the blocks or sub groups are learning math from a video game and learning it from traditional classroom activities.
So the best way to control the bias is by randomly assigning students to the different groups.
A load of mass 120kg is raised
vertically through a height of 2m in
30s by a machine whose efficiency,
is 100% Calculate the power generated
by the machine
Answer: P = 120 kg·9.81 m/s² · 2 m / 30 s = 78 W
Explanation: power P = Work done / time
Work is lifting work = mgh in which g = 9.81 m/s²
Time 30 s
A physics major is working to pay her college tuition by performing in a traveling carnival. She rides a motorcycle inside a hollow, transparent plastic sphere. After gaining sufficient speed, she travels in a vertical circle with a radius of 15.0 m. She has a mass of 80.0 kg and her motorcycle has mass 30.0 kg. What minimum speed must she have at the top of the circle for the motorcycle tires to remain in contact with the sphere
Answer:
v = 12.1 m/s
Explanation:
When at the top of the circle, there are two forces acting on the combined mass of the rider and the motorcycle.These are the force of gravity (downward) and the normal force, which is directed from the surface away from it, perpendicular to the surface.In this case, as the motorcycle runs in the interior of the circle, at the top point this force is completely vertical, and is also downward.Since the motorcycle is moving in a vertical circle, there must be a force, keeping the object moving around a circle.This force is the centripetal force, aims towards the center of the circle, and is just the net force aiming in this direction at any point.At the top point, this force is just the sum of the normal force and the weight of the mass of the rider and the motorcycle combined, as follows (we take the direction towards the center as positive):[tex]F_{c} = N + m*g (1)[/tex]
Now, we know that the centripetal force is related with the tangential speed at this point and the radius of the circle as follows:[tex]F_{c} = m*\frac{v^{2}}{r} (2)[/tex]
Since the normal force takes any value as needed to make (1) equal to (2), if the speed diminishes, it will be needed less force to keep the equality valid.In the limit, when the motorcyvle tires barely touch the surface, this normal force becomes zero.In this condition, from (1) and (2), we can find the minimum possible value of the speed that still keeps the motorcycle touching the surface, as follows:[tex]v_{min} =\sqrt{r*g} =\sqrt{15.0m*9.8m/s2} = 12.1 m/s (3)[/tex]The Hall effect can be used to determine the density of mobile electrons in a conductor. A thin strip of the material being investigated is immersed in a magnetic field and oriented so that its surface is perpendicular to the field. In a particular measurement, the magnetic field strength was 0.685 T, the strip was 0.107 mm thick, the current along the strip was 2.25 A, and the Hall voltage between the strip's edges was 2.59 mV.Find the density nof mobile electrons in the material. The elementary charge is 1.602×10−19 C.
Answer:
the density of mobile electrons in the material is 3.4716 × 10²⁵ m⁻³
Explanation:
Given the data in the question;
we make use of the following expression;
hall Voltage VH = IB / ned
where I = 2.25 A
B = 0.685 T
d = 0.107 mm = 0.107 × 10⁻³ m
e = 1.602×10⁻¹⁹ C
VH = 2.59 mV = 2.59 × 10⁻³ volt
n is the electron density
so from the form; VH = IB / ned
VHned = IB
n = IB / VHed
so we substitute
n = (2.25 × 0.685) / ( 2.59 × 10⁻³ × 1.602×10⁻¹⁹ × 0.107 × 10⁻³ )
n = 1.54125 / 4.4396226 × 10⁻²⁶
n = 3.4716 × 10²⁵ m⁻³
Therefore, the density of mobile electrons in the material is 3.4716 × 10²⁵ m⁻³
What is a overly-simplified definition of Einstein's theory of general relativity?
Answer:
the laws of physics are the same for all non-accelerating observers
Explanation:
What is the displacement for a driver who travels 10 km to get to a point that is 4 km from his starting point?
4 km
10 km
6 km
14 km
Answer:
6km
Explanation:
Four bicyclists travel different distances and times along a straight path. Which cyclist traveled with the greatest average
speed?
A
B
Cyclist 2 travels
87 min 22 s
Cyclist 4 travels
108 min 24 s
D
Cyclist 1 travels
95 m in 27 s
Cyclist 3 travels
106 m in 26 s
Answer:
The cyclist with the greatest average speed is Cyclist 4 with average speed of 4.5 m/s
Explanation:
Given;
Cyclist 1 travels 9 m in 27 s
Cyclist 2 travels 87 m in 22 s
Cyclist 3 travels 106 m in 26 s
Cyclist 4 travels 108 m in 24 s
Determine the average speed of the cyclists as follows;
Average speed of Cyclist 1: v = 9/27 = 0.33 m/s
Average speed of Cyclist 2: v = 87/22 = 3.96 m/s
Average speed of Cyclist 3: v = 106/26 = 4.08 m/s
Average speed of Cyclist 4: v = 108/24 = 4.5 m/s
Therefore, the cyclist with the greatest average speed is Cyclist 4 with average speed of 4.5 m/s
1. A silicon BJT is connected as shown in Fig 1, where RC = 3.6 k 2. VBE = 0.8 V. (10%)
(a) Predict Ic and specify Rp to establish Vce at 5 V.(5%)
(b) The BJT is said to be in forward-reverse bias. Explain what is meant by this. (5%)
Answer:
The circuit is missing attached below is the required circuit
answer :
a) Ic = 1.944 mA
Rp = 288.66 kΩ
b) The Emitter-base Junction of the BJT is forward biased while its collector-base junction is reverse biased
Explanation:
Rc = 3.6 kΩ
VBE = 0.8 v
1) predict Ic and specify Rp to establish Vce at 5 V
we will apply Kirchhoff's voltage law to resolve this
solution attached below
b ) The BJT is said to be in Forward reverse bias because The Emitter-base Junction of the BJT is forward biased while its collector-base junction is reverse biased
An elevator suspended by a vertical cable is moving downward at a constant speed. The tension in the cable must be A) greater than the weight of the elevator. B) less than the weight of the elevator. C) equal to the weight of the elevator.
Answer:
(C) because the elevator is not accelerating
Note F = M a = M g (the resultant force on the elevator is due to gravity)
or Fup = Fc the force exerted on the elevator by the cable
and Fdown = Fe the force exerted on the elevator by gravity
F = M a = Fup - Fdown = zero resultant force on elevator
What season is the Southern hemisphere in
Answer:
hope this answer helps this is what I understand
Answer:
In the southern hemisphere it is fall but almost winter
Explanation:
They are 6 months ahead of the northern hemisphere. at least thats
how I think about it
Rubbing two objects together turns the energy of motion into heat energy because of _____
fuel
conduction
friction
electricity
plssssssssssssssss answer correctly
Answer:
Friction
Explanation:
Friction is a force that opposes motion
Answer:
Friction is your answer ☺️. If I'm right so,
Please mark me as brainliest. thanks!!
Question 11 of 15
Which of the following compounds is carbon tetrahydride?
A. CaH4
B. CH4
C. CaH
D. CAH
the correct answer would be "B"
see bellow
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Answer:
third, The water has potential energy at the top of the waterfall and increasing kinetic energy as it falls.
Explanation:
Water at the top is not falling, but will fall soon, so has potential energy. It has increasing kinetic energy as it falls because the speed of water falling increases.
As a part of a project to construct a Rube Goldberg machine, a student wishes to construct a spring-loaded cube launcher. For examples of Rube Goldberg machines, see the beautiful Cog video or the Mythbusters Happy Holidays Rube Machine. Our student plans to trigger the release of the spring with a falling ball. The small cube to be launched has a mass of 119.0 grams. The available spring is a very stiff but light spring that has a spring constant of 461.0 N/m (the spring is so light that it may be considered massless). The spring will be mounted at the bottom of a wooden ramp which makes an angle of 50.0 degrees with the horizontal; the length of the spring is parallel to the ramp with the lower end of the spring fixed in place. For simplicity, assume that the part of the wooden ramp which is underneath the spring is highly polished and very slick; you may assume no friction on the cube by the ramp when the cube is moving on this portion of the ramp. For the rest of the wooden ramp, the coefficients of friction between the ramp surface and the cube surface are 0.590 for static friction and 0.470 for kinetic friction. Measured from the equilibrium position of the free end of the mounted spring, the distance to the top of the ramp is 17.0 cm (this is measured along the ramp) The plan is to compress the spring and maintain the compression with a simple trigger, which will be released by a falling ball. The cube will be at rest on the free end of the compressed spring. When the trigger is released, the spring will expand, shooting the cube up the ramp. The desired speed for the cube when it reaches the top of the ramp (where the cube will leave the ramp as a projectile to continue the Rube Goldberg sequence) is 45.0 cm/s. Your ultimate task will be to calculate the necessary amount of compression for the spring. The Spring is Compressed by 5.90 cm Before attempting the ultimate task, answer the following questions (Parts A-B) for the case in which the spring is compressed by 5.90 cm and then released, shooting the cube up the ramp and into the air.
A) Find the work done on the cube by the spring during the time that the cube is in contact with the spring.
B) What is the speed of the cube at the the instant just before the sliding cube leaves the ramp?
Answer:
1. The work done on the cube during the time the cube is in contact with the spring is 0.8023705 J
2. The speed of the cube at the instant just before the sliding cube leaves the ramp is approximately 31.5 cm/s
Explanation:
The given parameters of the Rube Goldberg machine are;
The distance from the free end of the spring to the top of the ramp, d = 17.0 cm = 0.17 m
The mass of the small cube to be launched, m = 119.0 g = 0.119 kg
The spring constant of the spring, k = 461.0 N/m
The angle of elevation of the ramp to the horizontal, θ = 50.0°
The coefficient of static friction of the wood, [tex]\mu_s[/tex] = 0.590
The coefficient of dynamic friction of the wood, [tex]\mu_k[/tex] = 0.470
The velocity of the cube at the top of the ramp, v = 45.0 cm/s = 0.45 m/s
The amount by which the cube is compressed, x = 5.90 cm = 0.059 m
The work done on the cube during the time the cube is in contact with the spring = The energy of the spring, E = (1/2)·k·x²
∴ E = (1/2) × 461.0 N/m × (0.059 m)² = 0.8023705 J
The work done on the cube during the time the cube is in contact with the spring= E = 0.8023705 J
2. The frictional force, [tex]F_f[/tex] = [tex]\mu_k[/tex]·m·g·cos(θ)
∴ [tex]F_f[/tex] = 0.470 × 0.119 × 9.8 × cos(50) ≈ 0.35232 N
The work loss to friction, W = [tex]F_f[/tex] × d
∴ W = 0.35232 N × 0.17 m ≈ 0.05989 J
The work lost to friction, W ≈ 0.05989 J
The potential energy of the cube at the top of the ramp, P.E. = m·g·h
∴ P.E. = 0.119 kg × 9.8 m/s² × 0.17 m × sin(50°) ≈ 0.151871375 J
By conservation of energy principle, the Kinetic Energy of the cube at the top of the ramp, K.E. = E - W - P.E.
∴ K.E. = 0.8023705 J - 0.05989 J - 0.151871375 J ≈ 0.590609125 J
K.E. = (1/2)·m·v²
Where;
v = The speed of the cube at the instant just before the sliding cube leaves the ramp
∴ K.E. = (1/2) × 0.119 kg × v² ≈ 0.590609125 J
v² ≈ 0.590609125 J/((1/2) × 0.119 kg) ≈ 9.92620378 m²/s²
v = √(9.92620378 m²/s²) ≈ 3.15058785 m/s ≈ 31.5 cm/s
The speed of the cube at the instant just before the sliding cube leaves the ramp, v ≈ 31.5 cm/s.
The slope of a displacement time graph for a uniform motion represent what
Answer:
Velocity.
Explanation:
The slope of a displacement time graph for a uniform motion represent the gradient of the line i.e. the velocity of the object.
The velocity of an object is given by :
v = d/t
Where
d is displacement
t is time
Hence, the slope of the displacement-time graph gives the velocity of the object.
2) How much work is required to pull a sled 15
meters if you use 30N of force?
2 people
Explanation:
Classes are canceled due to snow, so you take advantage of the extra time to conduct some physics experiments. You fasten a large toy rocket to the back of a sled and take the modified sled to a large, flat, snowy field. You ignite the rocket and observe that the sled accelerates from rest in the forward direction at a rate of 11.5 m/s^2 for a time period of 3.30 s. After this time period, the rocket engine abruptly shuts off, and the sled subsequently undergoes a constant backward acceleration due to friction of 4.15 m/s^2.
Required:
a. After the rocket turns off, how much time does it take for the sled to come to a stop?
b. By the time the sled finally comes to a rest, how far has it traveled from its starting point?
Answer:
a) t = 9.2s
b) Δx = 242.2 m
Explanation:
a)
In order to find the time that the sled traveled since the rocket was turned off, we need to find the first the speed that it had at that moment.Applying the definition of accceleration, since we know that the sled started from rest, we can find the value of the final speed (for this part) as follows:[tex]v_{f1} = a_{1} * t_{1} = 11.5m/s2* 3.30 s = 38.0 m/s (1)[/tex]
This speed, is just the initial speed for the second part, so we can find the time traveled from the moment the rocket was turned off until it came to an stop, as follows:[tex]t_{2} = \frac{v_{f1}}{a_{2} } = \frac{38m/s}{4.15m/s} = 9.2 s (2)[/tex]
b)
We need to find find first the displacement when the sled was accelerating.Assuming the acceleration is constant, since it started from rest, we can use the following kinematic equation:[tex]v_{f1} ^{2} = 2* a_{1} * x_{1} (3)[/tex]
Solving for x₁:[tex]x_{1} =\frac{v_{f1}^{2} }{2*a_{1}} =\frac{(38m/s)^{2} }{2*11.5m/s2} =62.8 m (4)[/tex]
In the same way, we can use the same equation, replacing the values of the final speed (which becomes zero), initial speed (which is the same as vf1), and a, which becomes -4.15 m/s2 as it is backwards.[tex]-v_{f1} ^{2} = 2* a_{2} * x_{2} (5)[/tex]
Solving for x₂:[tex]x_{2} =\frac{-v_{f1}^{2} }{2*a_{2}} =\frac{-(38m/s)^{2} }{2*(-4.15m/s)^2} =174.0 m (6)[/tex]
Δx = x₁ + x₂ = 68.2 m + 174.0 m = 242.2 m (7)Electromagnetic radiation is made up of wave components of electric and magnetic fields moving together. What form of energy is most closely associated with electromagnetic waves?
A.
light energy
B.
chemical energy
C.
electrical energy
D.
mechanical energy
Answer:
A) Because light is due to the electromagnetic fields (fields moving at the speed of light)
Note: Electrical energy is also used to describe the energy usage
in RLC circuits
A trapeze artist swings in simple harmonic motion with a period of 3.8 s.
Calculate the length of the cables supporting the trapeze. (g=9.81 m/s2)
5
Select the correct answer.
What is the current in a parallel circuit which has two resistors (17.2 ohms and
22.4 ohms) and a power source of 6.0 volts?
ОА.
0.30 amps
OB.
9.8 amps
OC.
0.61 amps
D.
1.2 amps
Reset
Next
Answer:
Current in a parallel circuit = 0.61 amps (Approx)
Explanation:
Given:
Voltage V = 6 volt
Two resistors = 17.2 , 22.4 in parallel circuit
Find:
Current in a parallel circuit
Computation:
1/R = 1/r1 + 1 / r2
1/R = 1/17.2 + 1 / 22.4
R = 9.73 ohms (Approx)
Current in a parallel circuit = V / R
Current in a parallel circuit = 6 / 9.73
Current in a parallel circuit = 0.61 amps (Approx)
What Kind of clothing would you most likely wear at 15 latitude?
A. Fleece or jacket and long pants
B. cotton shirts, light jacket, long pants
C. parka, gloves,insulated pants, heavy boots
D. shorts , sandals and T-shirts
Answer:
I'd say A, but I'm not 100% what kind of latitude you're referring to
Answer:
D. shorts, sandals and T-shirts
Explanation:
The 15th parallel north is a circle of latitude that is 15 degrees north of the Earth's equatorial plane. It crosses Africa, Asia, the Indian Ocean, the Pacific Ocean, Central America, the Caribbean and Atlantic Ocean. All these areas are all warm and weather for wearing shorts, sandals and T-shirts!
(Hope this helped! If so please mark this answer as brainliest!)
The terminal velocity of a person falling in air depends upon the weight and the area of the person facing the fluid. Find the terminal velocity (in meters per second and kilometers per hour) of an 86.0 kg skydiver falling in a pike (headfirst) position with a surface area of 0.145 m2. (Assume that the density of air is 1.21 kg/m3 and the drag coefficient of a skydiver in a pike position is 0.7. For each answer, enter a number.)
Answer:
terminal velocity is;
v = 117.54 m/s
v = 423.144 km/hr
Explanation:
Given the data in the question;
we know that, the force on a body due to gravity is;
[tex]F_g[/tex] = mg
where m is mass and g is acceleration due to gravity
Force of drag is;
[tex]F_d[/tex] = [tex]\frac{1}{2}[/tex]pCAv²
where p is the density of fluid, C is the drag coefficient, A is the area and v is the terminal velocity.
Terminal velocity is reach when the force of gravity is equal to the force of drag.
[tex]F_g = F_d[/tex]
mg = [tex]\frac{1}{2}[/tex]pCAv²
we solve for v
v = √( 2mg / pCA )
so we substitute in our values
v = √( [2×(86 kg)×9.8 m/s² ] / [ 1.21 kg/m³ × 0.7 × 0.145 m²] )
v = √( 1685.6 / 0.122015 )
v = √( 13814.6949 )
v = 117.54 m/s
v = ( 117.54 m/s × 3.6 ) = 423.144 km/hr
Therefore terminal velocity is;
v = 117.54 m/s
v = 423.144 km/hr
What is heredity and how does it influence physical fitness?
engaging in physical activities like agawang base helps me become
Explanation:
Agawang base is sport mainly played among children in eastern countries like Philippines. It is a game usually played using local props or instrument. Participants are divided into two teams with equal number of team members.
It becomes source of exercise for the players and improves their agility and endurance in the long run. It has also become tool of socializing and learning teamwork.
A student picks up two spheres that are the same size. One is made of steel and the other is made of aluminum. The student notices that the steel sphere feels much heavier than the aluminum sphere. He then holds one sphere in each hand at eye level and lets go of them at the same time. They fall to the floor. Which ball, if any, will hit the ground first and for what reason
Answer:
They will fall at the same time. This is because gravity accelerates all objects at the same speed, Earth's gravity being approximately 9.8m/s²
They'll both fall at the same time. This is because gravity accelerates everything at the same rate, with Earth's gravity being approximately 9.8 m/s2.
What is gravity with some instances?The energy that holds the gases inside the sun together. the force that causes a ball to fall after being thrown into the air the force that causes a car to coast downhill even when the gas pedal is not depressed the force that causes a glass to shatterGravity, also known as gravitation, affects all material objects in the universe. Gravity attracts any two objects or particles with nonzero mass toward one another. Gravity affects everything from subatomic particles to galaxy clusters. Gravity is the attraction force between two objects. It's what causes things to fall and keeps us from floating away into space. Gravity is a fundamental natural force.To learn more about gravity, refer to:
https://brainly.com/question/16275567
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