DL: Activity 2.3 Resistance
Complete the questions based on the Resistance presentation.
a. All resistors ___________ or _____________ the flow of electrons.
b. As resistance __________________ current _______________________
Answer:a) limits or opposes
b) increases, decreases
Explanation:Resistors are electrical devices used to resist, limit, oppose or hinder the flow of electrons in a circuit. This resistance causes a reduction in current and an increase in voltage in the circuit. In order words, as resistance increases, the current decreases and voltage increases.
This was further stated by Ohm's law that states that as long as the resistance in a wire/conductor remains constant, the voltage across it is directly proportional to the current flowing through a conductor. i.e
V = IR
Where;
R = constant called resistance
I = current flowing through the wire
V = voltage across the wire
A normal person consumes 2000 food calories a day. If a food calorie is equivalent to 4200 J of energy, use reasonable assumptions to calculate the number of kilograms of water that can be boiled away to steam starting from 20o C
Answer:
The mass of water boiled away as steam is 3.24 kg
Explanation:
Given;
total food calories consumed, 2000
1 calorie = 4,200 J
total energy of food consumed in joules, Q = 2,000 x 4,200 J = 8,400,000 J
initial temperature of the water, t₁ = 20 ⁰C
Assumptions:
(1) No energy is lost
(2) all the water is boiled to steam
(3) Energy needed to raise water to 100 ⁰C (q₁) plus Energy needed to boil the water to steam (q₂) = total energy of food consumed (Q)
(4) latent heat of vaporization of water, L = 2,260 kJ/kg
(5) specific heat capacity of water, c = 4,200 J/kg⁰C
let the mass of the water = m
Q = q₁ + q₂
Q = mcΔt + mL
Q = mc(t₂ - t₁) + mL
8,400,000 = 4,200(100 - 20)m + 2,260,000m
8,400,000 = 336,000m + 2,260,000m
8,400,000 = 2,596,000 m
m = 8,400,000/2,596,000
m = 3.24 kg
Therefore, the mass of water boiled away as steam is 3.24 kg
What do different forms of energy have in common?
A. They can push or pull on objects.
B. They give objects mass.
C. They can cause changes in matter.
D. They can cause objects to move.
Answer:
C because it changes your energy
Two blocks A and B with mA = 2.9 kg and mB = 0.87 kg are connected by a string of negligible mass. They rest on a frictionless horizontal surface. You pull on block A with a horizontal force of 6 N. Determine the tension in the string connecting the two blocks.
Answer:
Tension = 1.38 N
Explanation:
Given that:
Mass of block A [tex]m_A[/tex] = 2.9 kg
mass of block B [tex]m_B[/tex] = 0.87 kg
Force F = 6 N
Assume a = acceleration of the blocks.
Then:
[tex]m_A[/tex] (a) + [tex]m_B[/tex] (a) = 6
2.9a + 0.87a = 6
3.77a = 6
a = 6/3.77
a = 1.59 m/s²
Suppose T to be the tension in the string.
If we take a look at the forces acting on the first block, then:
F - T = [tex]m_A[/tex] (a)
T = F - [tex]m_A[/tex] (a)
T = 6 - 2.9(1.59)
T = 6 - 4.62
T = 1.38 N
Which of the following never cause a change in the motion of an object? A. Net forces B. Unbalanced forces O C. Balanced forces O D. Contact forces
Answer:
balanced force never changes its motion
A ball is spun around in circular motion such that its frequency is 10 Hz.
a. What is the period of its rotation?
b. How much time will be required to complete 100 rotations?
Answer:
a = 0.1 s b. 10 s
Explanation:
Given that,
The frequency in circular motion, f = 10 Hz
(a) Let T is the period of itsrotation. We know that,
T = 1/f
So,
T = 1/10
= 0.1 s
(b) Frequency is number of rotations per unit time. So,
[tex]t=\dfrac{n}{f}\\\\t=\dfrac{100}{10}\\\\t=10\ s[/tex]
Hence, this is the required solution.
A bicyclist rides 1.59 km due east, while the resistive force from the air has a magnitude of 7.00 N and points due west. The rider then turns around and rides 1.59 km due west, back to her starting point. The resistive force from the air on the return trip has a magnitude of 7.00 N and points due east. Find the work done by the resistive force during the round trip. Number Units
Answer:
The required work done by the resistive force = -22.3 kJ
Explanation:
We understand that the amount of work done for a force F and displacements is provided as the product of force multiplied by displacement, which can be represented as W = F.S
Now, when the cyclist travels east and returns west, the force and displacement directions will be opposite and they make an angle 180 degrees apart.
∴
W = -2 × 7.00 × 1590
W = -22260 J
W = -22.3 kJ
Two students are debating about the nature of light:a.Student 1: Looking at the chart, I see that light with a shorter wavelength has the highest frequency. But all light has the same speed.b.Student 2: I disagree with your Student 1. If light has a higher frequency, then it will have a faster speed than light with a lower energy.
Answer:
student 1 is right and student 2 is wrong
Explanation:
In the graph that the two students are observing is a graph of energy and frequency vs. wavelength, this graph is constructed using the relationship between a wave and its wavelength and frequency.
c = λ f
therefore for all waves we have the speed salami.
Therefore student 1 is right and student 2 is wrong
What is the energy stored in food?
Hey there!
The energy that is stored in food is called CHEMICAL ENERGY
So, when humans/people eat foods their bodies transfigure the energy that is stored which is known as the calories.
Whereas the chains (bonds) in the middle of the atoms in the food humans eat that break up the check mal reactions that has been taken into place and newer compounds will be created. Each food that you eat stores unlikeable amounts of energy
Answer: Chemical energy
Good luck on your assignment and enjoy your day!
~Amphitrite1040:)
Which element is the biggest contributor to Climate Change?
Answer:
carbon dioxide (CO2)
Explanation:
the burning or combustion of these fossil fuels creates gases that are released into the atmosphere. Of these gases, carbon dioxide (CO2) is the most common and is the gas most responsible for exacerbating the green- house effect that is changing global climate patterns.
A spherical light bulb dissipates 100W and is of 5cm diameter. Assume the emissivity is 0.8 and the irradiation is negligible. What is the surface temperature of this spherical light bulb
Answer:
[tex]T=728.9K[/tex]
Explanation:
Power [tex]P=100W[/tex]
Diameter [tex]d=5[/tex]
Radius [tex]r=2.5cm=>2.5*10^{-2}m[/tex]
Emissivity [tex]e=0.8[/tex]
Generally the equation for Area of Spherical bulb is mathematically given by
[tex]A=4\pi r^2[/tex]
[tex]A=4\pi (2.5*10^{-2}m)^2[/tex]
[tex]A=7.85*10^{-3}m^2[/tex]
Generally the equation for Emissive Power bulb is mathematically given by
[tex]E=e\mu AT^4[/tex]
Where
[tex]\mu=Boltzmann constants\\\\\mu=5.67*10^{-8}[/tex]
Therefore
[tex]T^4=\frac{E}{e\mu A}[/tex]
[tex]T^4=\frac{100}{0.8*5.67*10^{-8}*7.85*10^{-3}m^2}[/tex]
[tex]T=^4\sqrt{2.80*10^{11}}[/tex]
[tex]T=728.9K[/tex]
A volleyball is served at a speed of 8 / at an angle 35° above the horizontal. What is the speed of the ball when received by the opponent at the same height?
An oral solution has a dosage of 500 mg in 5 mL. If a 0.7 g dosage is required, how many mL must be given?
Answer:
7 mL
Explanation:
Given that:
mass of an oral solution = 500 mg
solution in mL = 5mL
Thus, the ratio = 5 mL/500 mg
= 0.01 mL/mg
since 1000 mg = 1g
∴
= 0.01 mL/mg × 1000 mg/1g
= 10 mL/g
Now, suppose the amount of 0.7 g dosage is required:
∴
the needed amount of mL will be:
= 10 mL/g × 0.7 g
= 7 mL
What is the current running through a parallel circuit containing a 10 V battery and three resistors, each 3 ohms
Answer:
the current through the circuit is 10 A.
Explanation:
Given;
voltage of the battery, V = 10 V
number of the parallel resistors, = 3
resistance of each resistor, r = 3 ohms
The equivalent resistance is calculated as;
[tex]\frac{1}{R_t} = \frac{1}{r_1}+ \frac{1}{r_2} + \frac{1}{r_3} \\\\\frac{1}{R_t} = \frac{1}{3}+ \frac{1}{3} + \frac{1}{3}\\\\\frac{1}{R_t} =\frac{3}{3} \\\\\frac{1}{R_t} = 1\\\\R_t = 1 \ ohms[/tex]
The current through the circuit is calculated as;
V = IRt
I = V/Rt
I = 10/1
I = 10 A
Therefore, the current through the circuit is 10 A.
write the full form of MBBS pliz now
Answer:
The full form of MBBS is Bachelor of Medicine, Bachelor of Surgery
pls mark me brainliest :))
The full form of MBBS in India is 'Bachelor of Medicine, Bachelor of Surgery'. However, MBBS is an abbreviation of Medicinae Baccalaureus Baccalaureus Chirurgiae, which is the term used for this course in Latin.
A model plane has a mass of 0.75 kg and is flying 12 m above the ground
with a speed of 18 m/s. What is the total mechanical energy of the plane?
The acceleration due to gravity is 9.8 m/s2.
Answer:
Option C. 210 J.
Explanation:
From the question given above, the following data were obtained:
Mass (m) = 0.75 Kg
Height (h) = 12 m
Velocity (v) = 18 m/s
Acceleration due to gravity (g) = 9.8 m/s²
Total Mechanical energy (ME) =?
Next, we shall determine the potential energy of the plane. This can be obtained as follow:
Mass (m) = 0.75 Kg
Height (h) = 12 m
Acceleration due to gravity (g) = 9.8 m/s²
Potential energy (PE) =?
PE = mgh
PE = 0.75 × 9.8 × 12
PE = 88.2 J
Next, we shall determine the kinetic energy of the plane. This can be obtained as follow:
Mass (m) = 0.75 Kg
Velocity (v) = 18 m/s
Kinetic energy (KE) =?
KE = ½mv²
KE = ½ × 0.75 × 18²
KE = ½ × 0.75 × 324
KE = 121.5 J
Finally, we shall determine the total mechanical energy of the plane. This can be obtained as follow:
Potential energy (PE) = 88.2 J
Kinetic energy (KE) = 121.5 J
Total Mechanical energy (ME) =?
ME = PE + KE
ME = 88.2 + 121.5
ME = 209.7 J
ME ≈ 210 J
Therefore, the total mechanical energy of the plane is 210 J.
YO giving 49 dollars if you answer this question .
. ( )
Trace the flow of energy through the food pyramid, label the missing units of energy found at each level by calculating the change in energy
Answer:
Energy Flow
The chemical energy of food is the main source of energy required by all living organisms. This energy is transmitted to different trophic levels along the food chain. This energy flow is based on two different laws of thermodynamics:
First law of thermodynamics, that states that energy can neither be created nor destroyed, it can only change from one form to another.
Second law of thermodynamics, that states that as energy is transferred more and more of it is wasted.
Energy Flow in Ecosystem
The energy flow in the ecosystem is one of the major factors that support the survival of such a great number of organisms. For almost all organisms on earth, the primary source of energy is solar energy. It is amusing to find that we receive less than 50 per cent of the sun’s effective radiation on earth. When we say effective radiation, we mean the radiation, which can be used by plants to carry out photosynthesis.
Explanation:
Energy Flow in Ecosystem
The energy flow in the ecosystem is one of the major factors that support the survival of such a great number of organisms. For almost all organisms on earth, the primary source of energy is solar energy. It is amusing to find that we receive less than 50 per cent of the sun’s effective radiation on earth. When we say effective radiation, we mean the radiation, which can be used by plants to carry out photosynthesis.
Most of the sun’s radiation that falls on the earth is usually reflected back into space by the earth’s atmosphere. This effective radiation is termed as the Photosynthetically Active Radiation (PAR).
Overall, we receive about 40 to 50 percent of the energy having Photosynthetically Active Radiation and only around 2-10 percent of it is used by plants for the process of photosynthesis. Thus, this percent of PAR supports the entire world as plants are the producers in the ecosystem and all the other organisms are either directly or indirectly dependent on them for their survival.
The energy flow takes place via the food chain and food web. During the process of energy flow in the ecosystem, plants being the producers absorb sunlight with the help of the chloroplasts and a part of it is transformed into chemical energy in the process of photosynthesis.
This energy is stored in various organic products in the plants and passed on to the primary consumers in the food chain when the herbivores consume (primary consumers) the plants as food. Then conversion of chemical energy stored in plant products into kinetic energy occurs, degradation of energy will occur through its conversion into heat.
Then followed by the secondary consumers. When these herbivores are ingested by carnivores of the first order (secondary consumers) further degradation will occur. Finally, when tertiary consumers consume the carnivores, energy will again be degraded. Thus, the energy flow is unidirectional in nature.
Moreover, in a food chain, the energy flow follows the 10 percent law. According to this law, only 10 percent of energy is transferred from one trophic level to the other; rest is lost into the atmosphere. This is clearly explained in the following figure and is represented as an energy pyramid.
An open 1-m-diameter tank contains water at a depth of 0.5 m when at rest. As the tank is rotated about its vertical axis the center of the fluid surface is depressed. At what angular velocity will the bottom of the tank first be exposed
Answer:
Angular velocity (w) = 8.86 rad/s
Explanation:
Angular velocity (w) = [tex]\sqrt{} 4ghi/R^{2}[/tex]
g= 9.81 m/s
R= 0.5
hi (initial depth) = 0.5m
Hence= [tex]\sqrt4* 9.81* 0.5/0.5^{2}[/tex] = 8.86 rad/s
3. How can a generator that otherwise produces AC
current be modified to produce DC current?
A sample contains 36 g of a radioactive isotope. How much radioactive isotope remains in the sample after 3 half-lives?
A. 12 g
B. 18 g
C. 4.5 g
D. 9 g
Answer:
Option "C": "4.5 g"
Explanation:
N0 = 36 g, Let half-life is T.
t = 3 T, n is number of half lives = t / T = 3
By using the decay law of radioactivity
N / N0 = (1 / 2)^n
where
"N0" be the "initial amount"
"N" be the "amount left"
"n" be the "number of half-lives"
N / 36 = (1/2)^3
N / 36 = 1 / 8
N = 36 / 8 = 4.5 g
A 500-nm wavelength light in vacuum illuminates a soap film with an index of refraction of 1.33. Air (n=1.00) is on both sides of the film. If the light strikes the film nearly perpindicularly, what is the smallest film thickness such that the film appears bright?
ANS --> 94.0
Please show your work as to how to end up with this answer.
Answer:
Wavelength of light in film (let y = lambda)
y = 500 nm / (4/3) = 375 nm
There will be a phase change at the air/film interface (not the other side)
S = 4 t thickness of film = S/4 where S equals 1 wavelength
This is because of the phase change at one surface
375 nm = 4 * t
t = 93.8 nm
A 0.200 m wire is moved parallel to a 0.500 T
magnetic field at a speed of 1.50 m/s. What emf is
induced across the ends of the wire?
Answer:
The required emf moved across the wire is zero
Explanation:
For a moving charge particle, the magnetic force can be determined by using the formula;
[tex]\varepsilon = Bvlsin \theta[/tex]
since the wire moves in parallel, the angle [tex]\theta[/tex] between magnetic field and velocity = 0°
B = 0.500 T
v = 1.50 m/s
l = 0.200 m
∴
[tex]\varepsilon = (0.500 \ T )(1.50 \ m/s) \times (0.200 \ m)\times sin (0)[/tex]
[tex]\varepsilon = 0.15\times sin (0)[/tex]
[tex]\varepsilon = 0[/tex]
potential Energy is associated with position
True or false
Answer:
yes.
Explanation:
potential Energy is associated with position
Answer:
true
Explanation:
the energy possessed by a body by virtue of its position or configuration is called potential energy.Everything at a height from the earth surface posseses potential energy.
A 5.0 A electric current passes through an aluminum wire of 4.0~\times~10^{-6}~m^2 cross-sectional area. Aluminum has one free electron per atom. The density of aluminum is 2.7~grams/cm^3, and the aluminum molar mass is 27 g. What is the electron number density (the number of electrons per unit volume) in the wire
Answer: The electron number density (the number of electrons per unit volume) in the wire is [tex]6.0 \times 10^{28} m^{-3}[/tex].
Explanation:
Given: Current = 5.0 A
Area = [tex]4.0 \times 10^{-6} m^{2}[/tex]
Density = 2.7 [tex]g/cm^{3}[/tex], Molar mass = 27 g
The electron density is calculated as follows.
[tex]n = \frac{density}{mass per atom}\\= \frac{\rho}{\frac{M}{N_{A}}}\\[/tex]
where,
[tex]\rho[/tex] = density
M = molar mass
[tex]N_{A}[/tex] = Avogadro's number
Substitute the values into above formula as follows.
[tex]n = \frac{\rho \times N_{A}}{M}\\= \frac{2.7 g/cm^{3} \times 6.02 \times 10^{23}/mol}{27 g/mol}\\= \frac{16.254 \times 10^{23}}{27} cm^{3}\\= 0.602 \times 10^{23} \times \frac{10^{6} cm^{3}}{1 m^{3}}\\= 6.0 \times 10^{28} m^{-3}[/tex]
Thus, we can conclude that the electron number density (the number of electrons per unit volume) in the wire is [tex]6.0 \times 10^{28} m^{-3}[/tex].
6) The temperature of 10 kg of a substance rises by 55°C when heated. Calculate the
temperature rise when 22 kg of the substance is heated with the same quantity of heat.
Answer:
121
Explanation:
When a person sits erect, increasing the vertical position of their brain by 38.6 cm, the heart must continue to pump blood to the brain at the same rate. (a) What is the gain in gravitational potential energy (in J) for 110 mL of blood raised 38.6 cm
Answer:
the gain in gravitational potential energy is 0.4369 J
Explanation:
Given the data in the question;
from the definition of density, we know that;
ρ = m / V
where ρ is density, m is the mass and V is the volume.
Now, lets make mass the subject of the formula
m = ρV ------ let this be equation 1
Now, we know that potential energy PE = mgh ------- let this be equation 2
where m is mass, g is acceleration due gravity, and h is the height.
substitute equation 1 into 2
PE = ρVgh
given that; V = 110 mL = 110 × 10⁻⁶ m³, h = 38.6 cm = 38.6 × 10⁻² m, g = 9.8 m/s², ρ = 1.05 × 10³ kg/m³
we substitute
PE = (1.05 × 10³ kg/m³) × (110 × 10⁻⁶ m³) × 9.8 m/s² × 38.6 × 10⁻² m
PE = 0.4369 J
Therefore, the gain in gravitational potential energy is 0.4369 J
A positive electric charge is moved at a constant speed between two locations in an electric field, with no work done by or against the field at any time during the motion. This situation can occur only if the
Answer:
The options are
A) charge is moved in the direction of the field
(B) charge is moved opposite to the direction of the field
(C) charge is moved perpendicular to an equipotential line
(D) charge is moved along an equipotential line
(E) electric field is uniform
The answer is (D) charge is moved along an equipotential line
For all the criteria in the question to be met it means that the motion is perpendicular to the field and the force is perpendicular to the displacement of the charge respectively. In this scenario,
Change in velocity is zero. Work can be calculated by multiplying charge and change in velocity which when calculated will give zero.
What was the earliest energy source for humans?
A. coal
B. oil
C. natural gas
D. wood
Answer:
i think its oil
Explanation:
It was made & used as early as the fourth century BC.
Adverb of place:
1
Adverb of time:
2
Adverb of place:
3
Adverb of time:
4
Adverb of place:
5
Answer:
1 there,here, somewhere,nowhere,everywhere
2.now,yesterday,then,
find the equivalent resistance.
Answer:
Explanation:
Note the connection between D-L-H shorts out the resistors on the right. Those 4 resistors can be ignored.
The connection between D-L-K means the 2 resistors between C-D and C-K are in parallel. The equivalent resistance of 2 6-ohm resistors in parallel is 3 ohms.
Similarly the connection between K-L-H means the 2 resistors between J-K and J-H are in parallel. The equivalent resistance of 2 6-ohm resistors in parallel is 3 ohms.
Adding the resistors in series together:
A-C-L-J-D = 6 + 3 + 3 + 6
= 18 ohms
Wind, hydropower, and solar can all be used to make ___
Answer: reusable energy or just energy but i think its just energy
Explanation:
