a. cool air warms as it mixes with denser air
Explanation:
c. warm air is displaced by cooler denser air
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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.
Which type of reactions usually happens slowest?
Answer:
option b is correct..................
Help me frfr I don’t understand
The points are
(1,10)
(6,0)
[tex]\boxed{\sf slope(m)=\dfrac{y_2-y_1}{x_2-x_1}}[/tex]
[tex]\\ \sf\longmapsto m=\dfrac{0-10}{6-1}[/tex]
[tex]\\ \sf\longmapsto m=\dfrac{-10}{5}[/tex]
[tex]\\ \sf\longmapsto m=-2[/tex]
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
Why do scientists not use US customary units when reporting their data?
One of the scientist's jobs is to report the results of his experiments to all the other scientists in the world.
There isn't a single real science shop anywhere in the world that uses the US customary system of units. Not one.
Even in the measly three countries that use it for measuring carpet, pumping gas, and weighing fish ... Myanmar, Liberia, an the USA ... the scientists do their work in the SI/MKS/metric system.
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
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.
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
A cricketer throws a ball sideways with an initial velocity of 30 m/s. She releases the ball from a height of 1.3m. Calculate how far the ball travels before hitting the ground.
Answer:
78.34
Explanation:
1.3/30=78.3m
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.
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.
help with this physics question please :)
Answer:
is that rm in you profile pic
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
A ferrari has a mass of 1485kg.what is it's weight on Earth
F = m · g
m = 1485 kg
g = 10 N/kg
F = 1485 kg · 10 N/kg = 14 850 N = 14,85 kN
Answer: The weight on Earth is 14,85 kN.
An object moving north with an initial velocity of 14 m/s accelerates 5 m/s2 for 20 seconds. What is the final velocity of the object?
39 m/s
90 m/s
114 m/s
414 m/s
Answer:
option C
Explanation:
Final velocity of the object is 114 m / s. Hence, final velocity of the object is 114 m / s.
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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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.
Write down the role played by four digestive juices in digestion and the
organs which secrete them.
Answer:
Digestive juices secreted by various organs such as salivary glands in the mouth, stomach, liver and pancreas help in the process of digestion of food. Saliva secreted by the salivary glands in the mouth aids in the breakdown of starch present in the food to simple sugar
Explanation:
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.
A particular electric car is supplied with 300 kJ of chemical energy by the battery. Of this, a total of 70.5 kJ of energy is wasted as heat.
Calculate the overall efficiency of the electric car.
Supplied energy=300kJ
Wasted energy=70.5JUsed energy:-
[tex]\\ \sf\longmapsto 300-70.5=229.5kJ[/tex]
We know
[tex]\boxed{\sf Efficiency=\dfrac{Used\:Energy}{Supplied\:Energy}\times 100}[/tex]
[tex]\\ \sf\longmapsto Efficiency=\dfrac{229.5}{300}\times 100[/tex]
[tex]\\ \sf\longmapsto Efficiency=\dfrac{229.5}{3}[/tex]
[tex]\\ \sf\longmapsto Efficiency=76.5\%[/tex]
The overall efficiency of the electric car = 76.5 %
To find the efficiency the given values are:
Energy supplied = 300 kJ
Energy wasted = 70.5 kJ
Define efficiency and calculate the value of efficiency.In the system the output energy is compared to the input energy is known as efficiency. That can be written as percentage ratio of output energy to the input energy.
Formula of efficiency is,
Efficiency = ( E out / E in ) × 100
Here, Energy supplied = 300 kJ
so, energy used = Energy supplied - Energy wasted
= 300 - 70.5
= 229.5 kJ
Thus, substituting E out = 300 kJ , E in = 229.5 kJ
Efficiency = ( 229.5 / 300 ) ×100
= 229.5 / 3
= 76.5
Hence, The overall efficiency of the electric car is 76.5 %
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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]
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 .
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°.
A sound frequency 100Hz and wavelength 3.34m is travelling through air, calculate the Velocity of sound in air.
Answer:
334m/s
Explanation:
If you take the data you gave and insert it into the equation f=v/λ the frequency would come out to be 3.34m
334 m/s is the Velocity of sound in air.
What is the velocity of a wave?Wave velocity in common usage refers to speed, although, properly, velocity implies both speed and direction.
The velocity of a wave is equal to the product of its wavelength and frequency (number of vibrations per second) and is independent of its intensity.
Mathematically , v=fλ
According to the question,
Sound frequency (f) = 100Hz
Wavelength (λ)= 3.34m
Computing the values in the formula,
v=fλ
v = 100Hz x 3.34m
v= 334m/s
Therefore,
Velocity of sound in air is 334 m/s.
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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.
(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
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
.
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)
