20. A semiconductor is a
crystalline solid that conducts current under any condition
metallic solid that conducts current under any condition
metallic solid that conducts current under certain conditions
crystalline solid that conducts current under certain conditions
Answer:
D. crystalline solid that conducts current under certain conditions
Explanation:
Semiconductors are crystalline solids that has the ability to conduct electrical currents but on certain conditions e.g heat. The conduction of semiconductors is less than that of conductors (metals) but more than insulators (nonmetals), hence, they are said to be intermediates of conductors and insulators in terms of electrical conductivity.
Examples of semiconductors are silicon, boron, carbon, germanium, arsenic etc.
A pendulum of mass 18 kg is released from rest at some height, as shown by
point A in the image below. At the bottom of its arc at point B, it is traveling at
a speed of 17 m/s. What is the approximate amount of energy that has been
lost due to friction and air resistance? (Recall that a=98 m/s2
By the work-energy theorem, the total work done on the mass as it swings is
W = ∆K = 1/2 (18 kg) (17 m/s)² = 153 J
No work is done by the tension in the string, since it's directed perpendicular to the mass at every point in the arc. Similarly, the component of the mass's weight mg pointing perpendicular to the arc also performs no work.
If we ignore friction/drag for the moment, the only remaining force is the parallel component of weight, which performs mgh = (176.4 N) h of work, where h is the vertical distance between points A and B.
Now, if w is the amount of work done by friction/air resistance, then
(176.4 N) h - w = 153 J
If you know the starting height h, then you can solve for w.
A hockey puck has a mass of 0.21 kg. If the hockey puck
is moving with 74 J of kinetic energy, what is its speed?
Show all your work.
Answer:
v = 26.54 m/s
Explanation:
Given that,
The mass of a hockey puck, m = 0.21 kg
The kinetic energy of the hockey puck, E= 74 J
We need to find the speed of the hockey puck. Let the speed is v. We know that, the kinetic energy is given by :
[tex]E=\dfrac{1}{2}mv^2[/tex]
Where
v is the speed
So,
[tex]v=\sqrt{\dfrac{2E}{m}} \\\\v=\sqrt{\dfrac{2\times 74}{0.21}} \\\\v=26.54\ m/s[/tex]
So, the speed of the hockey puck is 26.54 m/s.
what is projectile motion
[tex]\boxed{\large{\bold{\textbf{\textsf{{\color{blue}{Answer}}}}}}:)}[/tex]
[tex]\sf{\qquad{\qquad{\underline{\underline{ Projectile~motion }}}}}[/tex]
If an object is given an initial velocity in any direction and then allowed to travel freely under gravity only, it is called a projectile motion.
It is basically 3 types
horizontally projectile motion oblique projectile motion included plane projectile motionThe path followed by a projectile is called its trajectory.
Projectile motion is when an object moves in a bilaterally symmetrical, parabolic path.
The path that the object follows is called its trajectory.
Projectile motion only occurs when there is one force applied at the beginning, after which the only influence on the trajectory is that of gravity
An electron enters the magnetic field at right angle from left B into paper. The electron will be deflected?
Answer:
According to this direction of force is perpendicular to the direction of current and magnetic field. Therefore force is opposite to electron into the paper at 90°.
absolute potential difference ,due of point charge of 1C at a distance of 1 m is given by
Answer:
[tex] \implies U = \dfrac{kq}{r} [/tex]
[tex]\implies U = \dfrac{9 \times {10}^{9} \times 1}{1} [/tex]
[tex]\implies U = 9 \times {10}^{9} \: J[/tex]
We have that absolute potential difference ,due of point charge of 1C at a distance of 1 m is given by
[tex]\rho=9x10 ^{10}J[/tex]
From the question we are told that
point charge of 1C at a distance of 1 m
Generally the equation for the Electrostatic potential energy is mathematically given as
[tex]\rho=\frac{kq_1q_2}{r}[/tex]
Where k is a constant
[tex]k=9*10^9Nm^2/c^2[/tex]
Therefore
[tex]\rho=\frac{(9*10^9)1*10^(-6)*1*10^{-6}}{1}[/tex]
[tex]\rho=9x10 ^{10}J[/tex]
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A girl is travelling on her bike at a speed 2.59 m/s. If the
girl and her bike have a kinetic energy of 190 J, what is
the combined mass of the girl and her bike? Show all
your work
Answer:
Mass, m = 146.72 kilograms
Explanation:
Given the following data;
Kinetic energy = 190 J
Velocity = 2.59 m/s
To find the combined mass of the girl and her bike;
Kinetic energy can be defined as an energy possessed by an object or body due to its motion.
Mathematically, kinetic energy is given by the formula;
K.E = ½mv²
Where;
K.E represents kinetic energy measured in Joules.
M represents mass measured in kilograms.
V represents velocity measured in metres per seconds square.
190 = ½*m*2.59
Cross-multiplying, we have:
380 = 2.59m
Mass, m = 380/2.59
Mass, m = 146.72 kilograms
Two astronomy students travel to South Dakota. One stands on Earth’s surface and enjoys some sunshine. At the same time, the other descends into a gold mine where neutrinos are detected, arriving in time to detect the creation of a new radioactive argon nucleus. Although the photon at the surface and the neutrinos in the mine arrive at the same time, they have had very different histories. Describe the differences.
Answer:
The photon takes millions of years to reach the Surface of the sun while the Neutrinos travelling at the speed of light reaches the surface of the sun in approximately 2 seconds
The Photon is million year old while the neutrino is just some minutes old as observed by the student .
Explanation:
Although The Photon ( sunshine from the sun's surface ) heating up the student standing on the Earth's surface and the neutrinos discovered by the other student inside the gold mine are both formed in the Sun's core.
The difference between both are
The photon takes millions of years to reach the Surface of the sun while the Neutrinos travelling at the speed of light reaches the surface of the sun in approximately 2 seconds
The Photon is million year old while the neutrino is just some minutes old as observed by the student .
(d) Below shows a hydraulic press with a pump piston of area 4 cm2 and a ram area of
12 cm2 . IF A force of 300 N is applied on the pump piston, find:
(i)the maximum load on the ram.
(ii) the velocity ratio of the machine.
(iii) the mechanical advantage of the machine.
(iv)the efficiency of the machine.
Answer:
Explanation:
hi
8. A copper container of 84g mass contains 84g of water at 20°C. 46g of water at 200°C is mixed with water in the copper ontainer. What is the final temperature of the water? Specific heat capacity of water = 4200 J kg-1 °C-1, Specific heat capacity of copper = 400 J kg-1 °C-1
Answer:
80 °C
Explanation:
The heat transfer parameters for the water and copper container are;
Mass of the copper container, m₁ = 84 g
Mass of the water in the container, m₂ = 84 g
Initial temperature of the water in the container, T₂ = 20°C
Mass of the hot water added, m₃ = 46 g
Initial temperature of the hot water, T₃ = 200°C
Specific heat capacity of water, c₂ = 4,200 J·kg⁻¹·°C⁻¹
Specific heat capacity of copper, c₁ = 400 J·kg⁻¹·C⁻¹
The formula for the specific heat, ΔQ = m·c·ΔT
The heat lost by the hot water = The heat gained by the container the and the cold water
The formula for the specific heat of the mixture is presented as follows;
m₃ × c₃ × (T₃ - T) = m₁ × c₁ × (T - T₁) + m₂ × c₂ × (T - T₂)
Where T represents the final temperature of the water
Therefore, by plugging in the values, we get;
46 × 4200 × (200 - T) = 84 × 400 × (T - 20) + 84 × 4200 × (T - 20)
38640000 - 193200·T = 386400·T - 7728000
38640000 + 7728000 = 46368000 = 386400·T + 193200·T = 579,600·T
∴ T = 46368000/579,600 = 80
The final temperature of the water, T = 80°C
Pls help asap!!
A bucket contains hot water at 95°c. A man wants to bath with water at 40°c. What is the ratio of the mass of hot water to the mass of cold water that he needs.
Answer:
55
Explanation:95-40=55
i hope i did the math right if i didnt please tell me
HELP ASAP
A. 1.09 A
B. 1.20 A
C.0.910 A
D. 0.830 A
Answer:
The answer should be: 1.20 A
Explanation:
When developing an experiment design, which could a scientist take to improve the quality of the results?
The options missing are;
A. Make only a few changes to the manipulated variable.
B. Identify any biases about the answer to the scientific question.
C. Include as many details as possible when writing the conclusion.
D. Share her ideas through peer review.
Answer:
B. Identify any biases about the answer to the scientific question.
Explanation:
Since the question is asking what can be done to improve the quality of the results, it means what can the scientist do to make sure that the result answers the question properly and has little or no biases.
Thus, looking at the options, the only one that comes close to actually improving on the quality of the results before finalizing is option B where the scientist is to identify any biases.
For saving lives, what is the most important safety feature on a car? A. Air bag B. Safety Belt C. Anti-lock brakes
For saving lives the most important safety feature on a car is B. Safety Belt
What are safety features of a car ?Safety features of a car is a feature of a product designed to ensure or increase safety.
Air bag and Anti-lock brakes are the supplemental protection and designed to work best with combination with seat bells.
Air bag reduce the chance that upper body or head will strike the vehicle's interior during a crash alongside with belt that will also hold your upper body
so, the primary safety feature is seat belt and Air bag and Anti-lock brakes comes in secondary safety feature as they increases the safety and risk of getting an injury during any accident
correct answer is B. Safety Belt
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Which statement describes why energy is released in a nuclear fission reaction based on mass-energy equivalence?
A. For large nuclei, the mass of the original nucleus is greater than the mass of the products.
B. For large nuclei, the mass of the original nucleus is less than the mass of the products.
C. For small nuclei, the binding energy of the lighter nuclei is greater than the binding energy of the heavier nucleus.
D. For small nuclei, the binding energy of the lighter nuclei is less than the binding energy of the heavier nucleus.
Answer:
A is the answer!
Explanation:
Edge 2021
Answer:
A
Explanation:
Edge
Which of the following is evidence for continental drift?
Which is an outer planet?
Answer:
pluto
Explanation:
Dwarf because it is very minut
Answer:
I think Saturn.
Explanation:
I think the inner planets are Mercury, Venus, Earth and Mars whereas the outer ones are Jupiter, Saturn, Uranus and Neptune.
A parallel combination of a 1.47 μF capacitor and a 2.95 μF capacitor is connected in series to a 4.89 μF capacitor. This three‑capacitor combination is connected to a 15.5 V battery. Determine the charge on each capacitor.
Answer:
a. i. 35.96 μC b. i. 11.98 μC ii. 24.04 μC
Explanation:
We need to find the total capacitance of the system C.
The total capacitance of the parallel combination of a 1.47 μF capacitor and a 2.95 μF capacitor is C' = 1.47 μF + 2.95 μF = 4.42 μF.
C' = 4.42 μF is in series with the 4.89 μF capacitor and for a series combination of capacitors, we have the total capacitance, C from
1/C = 1/4.42 μF + 1/4.89 μF
1/C = (4.42 μF + 4.89 μF)/(4.42 μF × 4.89 μF)
1/C = 9.31 μF/21.6138 μF²
C = 21.6138/9.31 μF
C = 2.32 μF
So, the total charge in the circuit Q = CV where C = total capacitance = 2.32 μF and v = voltage = 15.5 V
So, Q = CV
Q = 2.32 μF × 15.5 V
Q = 35.96 μC
i. The charge on the 4.89 μF capacitor
Since the 4.89 μF is in series with C', the total charge flowing i the circuit is the total charge in the 4.89 μF capacitor. So, its charge Q = 35.96 μC
b. The charge in the 1.47 μF and 2.95 μF capacitors.
To find the charge in the 4.89 μF and 2.95 μF capacitors, we need to find the voltage across the combined parallel combination of a 1.47 μF capacitor and a 2.95 μF capacitor. The voltage, V' across the 4.89 μF capacitor, since Q = CV', V' = Q/C = 35.96 μC/4.89 μF = 7.35 V
So, the voltage V" across the combined parallel combination of a 1.47 μF capacitor and a 2.95 μF capacitor, C' is V" = 15.5 V - V' (since V' + V" = 15.5 V).
So, V" = 15.5 V - V'
V" = 15.5 V - 7.35 V
V" = 8.15 V
i. The charge on the 1.47 μF capacitor
Using Q' = CV" where Q' = charge across capacitor, C = 1.47 μF and V" = 8.15 V.
So, Q' = CV"
Q' = 1.47 μF × 8.15 V
Q' = 11.98 μC
ii. The charge on the 2.95 μF capacitor
Using Q" = CV" where Q' = charge across capacitor, C = 2.95 μF and V" = 8.15 V.
So, Q" = CV"
Q" = 2.95 μF × 8.15 V
Q" = 24.04 μC
if the pelican in item 3 was traveling at the same speed but was only 2.7m above the water, how far would the fish travel horizontally before hitting the water?
Answer:
5.66 m
Explanation:
From online sources, the speed in item 3 being referred to was discovered to be 7.62 m/s
Now, let's get the time of flight from one of Newton's equation of motion;
S = ut + ½gt²
Considering the vertical component, we have u = 0 m/s.
Thus;.
S = ½gt²
Plugging in the relevant values;
2.7 = ½ × 9.8 × t²
t² = 2.7/4.9
t = √(2.7/4.9)
t = 0.7423 s
Now, when we consider the horizontal component of the motion, we have;
S = vt
Where;
S is the distance the fish will travel horizontally before hitting the water.
v = 7.62 m/s
t = 0.7423
Thus
s = 7.62 × 0.7423
s ≈ 5.66 m
it will be easier to lift a load in wheel barrow if the load is moved towards the wheel. Give Reason.
Answer:
Here's your answer: The wheelbarrow's wheel and axle help the wheelbarrow to move without friction thus making it easier to push or pull. That's why it will be easier to lift a load in wheel barrow of the load is transferred towards the wheel.
Explanation:
Answer:
Explanation:
The wheel barrows wheel and axle helps the wheelbarrow to move without friction this making it easier to push or pull.thats why it will be easier to lift a load in a wheelbarrow if it's transferred towards the wheel..
Hope it helps
Why is it difficult to maintain constant speed of a vehicle?
Answer:
The road surface is always rough, so the frictional force between the tires and the road surface make it difficult to maintain constant speed because acceleration always changes.
Use the information below the answer the following 3 questions.
A 50 kg crate is being dragged across a floor by a force of 225 N at an angle of 40o from the horizontal. The crate is dragged a distance of 5.0 m and the frictional force is 60 N.
Question 2 (2 points)
Question 2 options:
The work done on the crate by the applied force is ___x102 Nm. (Give your answer with the correct number of sign digs and do not include units).
Question 3 (2 points)
Question 3 options:
The work done on the crate by the frictional force is -___x102 Nm. (Give your answer with the correct number of sign digs and do not include units).
Question 4 (2 points)
Question 4 options:
The net work done on the crate is ___x102 Nm. (Give your answer with the correct number of sign digs and do not include units).
Hint: Do not use rounded answers in subsequent calculations
Answer:
2. 8.62×10² Nm
3. 2.30×10² Nm
4. 6.32×10² Nm
Explanation:
2. Determination of the work done by the applied force.
Force (F) = 225 N
Distance (d) = 5 m
Angle (θ) = 40°
Workdone (Wd) =?
Wd = Fd × Cos θ
Wd = 225 × 5 × Cos 40
Wd = 8.62×10² Nm
3. Determination of the work done by the frictional force.
Frictional Force (Fբ) = 60 N
Distance (d) = 5 m
Angle (θ) = 40°
Workdone (Wd) =?
Wd = Fբd × Cos θ
Wd = 60 × 5 × Cos 40
Wd = 2.30×10² Nm
4. Determination of the net work done.
We'll begin by calculating the net force acting on the crate
Force applied (F) = 225 N
Frictional Force (Fբ) = 60 N
Net force (Fₙ) =?
Fₙ = F – Fբ
Fₙ = 225 – 60
Fₙ = 165 N
Finally, we shall determine the net Workdone. This can be obtained as follow:
Net force (Fₙ) = 165 N
Distance (d) = 5 m
Angle (θ) = 40°
Workdone (Wd) =?
Wd = Fₙd × Cos θ
Wd = 165 × 5 × Cos 40
Wd = 6.32×10² Nm
How can we measure electromotive force of a battery illustrated answer with the help of circuit diagram
Answer:
the emf of the cell can be determined by measuring the voltage across the cell using a voltmeter and the current in the circuit using an ammeter for various resistances.
you are pedaling forward on your bike. which of the following would decrease your acceleration?
A. A decrease in your mass
B. A increase in your applied force
C. An increase in your mass
D. An increase in your speed
Pedaling forward over the bike with the increase in your applied force would decrease your acceleration. Thus, option B is correct.
What is acceleration?Acceleration is define as the rate at which velocity changes with time, in terms of both speed and direction. The equation for acceleration is:
a=F/m
where, a = acceleration,
F = force applied
m = mass of the object
The acceleration of an object depends directly upon the net force acting upon the object, and inversely upon the mass of the object.
As the force acting upon an object is increased, the acceleration of the object is increased. As the mass of an object is increased, the acceleration of the object is decreased.
Therefore, if you are pedaling forward on your bike then a increase in your applied force would decrease your acceleration. Thus, option B is correct.
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Answer:
I just did it. A is right.
Explanation:
A rectangular coil of wire, 22.0 cm by 35.0 cm and carrying a current of 1.40 A, is oriented with the plane of its loop perpendicular to a uniform 1.50-T magnetic field pointing into the plane of the loop. Let the loop be in x-y Cartesian plane so that the long and short sides of the loop are parallel to x- and y-axis, respectively. The loop center is at the origin of x-y Cartesian plane. Note that the magnetic field is in the direction of the negative z-axis.a. Calculate: (i) the net force that the magnetic field exerts on the coil; (ii) the torque about the z-axis that the magnetic field exerts on the coil.b. The plane of the coil is now rotated through +30º from its initial orientation (the x-y plane of the Cartesian coordinate system that remains the same). Calculate: (i) the net force that the magnetic field exerts on the coil; (ii) the torque about the rotation axis that the magnetic field exerts on the coil.
Answer:
a) [tex]F_{net}=0[/tex]
b) [tex]T=0[/tex]
Explanation:
From the question we are told that:
Dimensions:
[tex]L*B=22.0*35.0cm[/tex]
Current [tex]I=1.40A[/tex]
Magnetic field [tex]B=1.40[/tex]
Therefore
[tex]Area=L*B[/tex]
[tex]A=22.0*35.0cm[/tex]
[tex]A=770cm=>770*0^{-4}[/tex]
a)
Generally Force on Looping gives
[tex]F_1-F_2[/tex]
[tex]F_3=F_4[/tex]
Therefore
[tex]F_{net}=0[/tex]
b)
Generally the equation for Torque is mathematically given by
[tex]T=i*Asin \theta[/tex]
Since A and B are on opposite direction
[tex]\theta=180[/tex]
Therefore
[tex]T=1.40*770*10^{-4}sin 180[/tex]
[tex]T=0[/tex]
HELP me
Which sentence best describes how the horse is doing work?
A It is using motion to transfer energy and force away from the heavy object
B it is using force to apply power and decrease the energy of the heavy object
C it is using energy to apply the force needed to move the object over a distance
D it is using power to force the heavy object to move over A certain distance
Define measurement with examples.
Explanation:
Measurement is defined as the act of measuring or the size of something. An example of measurement means the use of a ruler to determine the length of a piece of paper. An example of measurement is 15" by 25". ... The dimension, quantity, or capacity determined by measuring.
Measurement refers to the comparison of unknown physical quantity with a known quantity.
for eg. measurement of body while sewing clothes.......
What is the relationship between electric field lines and equipotential lines that you observed in doing the lab
Answer:
Explained below
Explanation:
Generally speaking, we know in physics that Electric field lines are lines which usually start at positive charges and deflect away from them to terminate at the negative charges. Meanwhile Equipotential lines are lines that are used to connect points located on the same electric potential.
Finally, in conclusion, electric field lines are usually lines that go through in a perpendicular manner across every equipotential lines.
.
What is the equation for work?
Work = force / distance
Work = force - distance
Work = force + distance
Work = force * distance
Answer:
Work = F X D
Explanation:
Work (J) equals Force (N) multiplied by Distance (M)
một vật m=1kg có động lượng bằng 10kg.m/s. động năng của vật là
