Answer: 27Ω
Explanation:
Quando o circuito está em série, a resistência total é igual ao somatório das resistências parciais do circuito.
If a 60 W light bulb and a 75 W light bulb operate from 150 V source, which bulb has a greater current in it?
60 W
75 W
Answer:
Since it us the resistance that causes the power output, it might be intuitive to think that more resistance produces more power but as P=I^2 * R one actually needs high current and low resistqnce. That means 75 W has lower resistance and higher current.
Now you may think that making the resistance very low, one gets the most power. Not so, as the circuit has wires, power source etc. All the have their resistance. In theory one gets the maximum power over a resistor when the resistor is half of the total resistance of the circuit. This in practice would be inefficient as one would lose half of the total power elsewhere. In practice circuits have fuses that limit the current and one gets the maximum power at the current the fuse is rated to. So if there is 20 A fuse, the maximum power is 2400 W and the corresponding resistance 6 ohm.
NEED ANSWER QUICK, WILL GIVE BRAINLIEST! How many nails do sapiens have?
A. 6
B. 10
C. 3
D. None
Answer:
nice calculations!
Explanation:
Can someone explain to me why Ohms law stops working when the temperature of the component increases?
Answer:
Ohm's law verifies that current directly varies with voltage, when resistance increases, current current decreases.
When temperature increases, the electrons gain more average kinetic energy increases and current increases as well.
In the same situation, resistance also increases because atoms of a component vibrate at higher amplitudes about their mean positions hence reducing the free path of electrons. This increases resistance, hence ohms law violated or disobeyed.
This generates the temperature coefficient of resistance
what's a magnet field
1. explain why nichrome wire used in the heater.
2. explain why copper wire not used in the heater.
Answer:
1. The reason why nichrome wire is used in a heater is due to the properties of nichrome which makes it a material of choice for heating application including;
i) The cost of manufacture of nichrome is low
ii) Nichrome has both high mechanical and creep strength, and therefore is suitable for installation and use in a wide setting
iii) Nichrome has a high resistance to electron flow, making it a good electrical heating element
iv) Nichrome has a high resistance to oxidation, such that it can be reused several times as a heater
v) The high ductility of nichrome allows it to be stretched and drawn around different vessels with contents to which heat is to be supplied
2. Copper wire is not used in heaters because according to Joule's law, the heat produced from the flow of electric current, 'I', through a material having a resistance, 'R', for a time, 't', is proportional to I²·R·t, and copper has a very low resistance, 'R', to the flow of electric current, and therefore, will not produce sufficient heat required at a given current level
Explanation:
Molten iron has a density of 7.0 g/cm. In its solid state, iron has a density of
8.0 g/cm?
Calculate the volume of 10 kg of molten iron.
Volume =
4. A motorist travels 406 km during a 9.0 hr period. What was the average speed in km/hr and m/s?
Answer:
45.11 kmph and 12.530 m/s
Explanation:
Average speed = Total distance travelled / Total time taken
406/9 gives the answer in kilometers
And we convert it to m/s by multiplying it with 1000/3600
Một dây dẫn đặt trong không khí có dòng điện I = 12A chạy qua, được gấp thành hình vuông cạnh a = 10cm. Xác định vectơ cường độ từ trường tại tâm O của hình vuông.
Answer:
The net magnetic field ta the center of square is[tex]1.36\times10^{-4} T[/tex].
Explanation:
Current, I = 12 A , side ,a = 10 cm = 0.1 m
Let the magnetic field due to the one side is B.
The magnetic field is given by
[tex]B = \frac{\mu o}{4\pi}\times \frac{I}{r}\times \left (Sin A +Sin B \right )\\\\B = 10^{-7}\times \frac{12}{0.05}\times \left ( sin 45 + sin 45 \right )\\\\B = 3.4\times 10^{-5} T[/tex]
Net magnetic field at the center of the square is
B' = 4 B
[tex]B'= 4\times 3.4\times 10^{-5}\\\\B' = 1.36\times10^{-4} T[/tex]
Marcel and Jose lifted 50 pounds as many times as they could. Marcel could lift the weight 25 times. Jose could lift the weight 30 times. Marcel and Jose can conclude that __________.
A.
Jose has better muscular endurance than Marcel
B.
Jose has better muscular strength than Marcel
C.
Marcel has better muscular strength than Jose
D.
Marcel has better muscular endurance than Jose
Answer:
A
Explanation:
An ohmic dipole of resistance 100 ohm is crossed by a current of intensity 120 ma. Calculates the voltage across this chemical dipole
Answer:
12.0 Volt
Explanation:
Step 1: Given data
Resistance of the ohmic dipole (R): 100 Ohm
Intensity of current (I): 120 mA (0.120 A)
Step 2: Calculate the voltage (V) across this chemical dipole
To calculate the voltage across the ohmic dipole, we will use Ohm's law.
I = V/R
V = I × R
V = 0.120 A × 100 Ohm = 12.0 V
In a wire, when elongation is 4 cm energy stored is E. if it is stretched by 4 cm,
then what amount of elastic potential energy will be stored in it?
plz don't spam
answer fast in imp
Answer:
4E
Explanation:
From the question given above, the following data were obtained:
Initial elongation (e₁) = 4 cm = 4/100 = 0.04 m
Initial energy (E₁) = E
Final elongation (e₂) = 0.04 + 0.04 = 0.08 m
Final energy (E₂) =?
The energy stored in a s spring is given by:
E = ½Ke²
Where
E => is the energy
K => is the spring constant
e => is the elongation
From:
E = ½Ke²
Energy is directly proportional to the elongation. Thus,
E₁/e₁² = E₂/e₂²
With the above formula, we can obtain the final energy as follow:
Initial elongation (e₁) = 0.04 m
Initial energy (E₁) = E
Final elongation (e₂) = 0.08 m
Final energy (E₂) =?
E₁/e₁² = E₂/e₂²
E / 0.04² = E₂ / 0.08²
E / 0.0016 = E₂ / 0.0064
Cross multiply
0.0016 × E₂ = 0.0064E
Divide both side by 0.0016
E₂ = 0.0064E / 0.0016
E₂ = 4E
Therefore, the final energy is 4 times the initial energy i.e 4E
Daniel wants to find out if he can notice the difference in light intensity when he adds some lit candles to a set of 50 lit candles. When he adds 5 candles to the set, he notices the difference in intensity half the time. However, when he adds less than 5 candles to his set, he does not notice any difference in the intensity of light. In this scenario, Daniel's difference threshold for detecting the change in light intensity is ________ lit candles.
Answer:
5
Explanation:
The light intensity may be defined as the strength of the light or the magnitude of its brightness that a source of light can produce.
The light threshold is the minimum intensity of the light that our eye can detect and the ability to adapt to darkness.
In the context, Daniel wishes to find if can notice the difference in the intensity of the light when he add 5 candles to the set of 50 candles.
He noticed that when he added 5 candles, he could notice the difference in the intensity and when he added less than 5 candles to the set of 50 candles he could not detect.
Thus, the difference threshold for Daniel to detect the change in the intensity of the light is 5 candles.
Q= Which one of the following statement is incorrect?
A. When a switch is closed in a circuit, no current flows.
B. A switch is a device for turning on and off an electric current.
C. An electric current is a complete loop around which a current can flow.
D. An electric current is a flow of charge
Answer:
A.
Explanation:
I think it might be the big number A
What would be the weight (in Newtons) of a person with a mass of 80 kg on Earth, where the acceleration due to gravity is approximately 9.8 m/s/s? *
please help asap
Answer:
ml tayo 1v1 durugin kita
Explanation:
ano takot ml 1v1
A 60 kg girl on a swing is pulled 1.5 meters back and then released. The girl oscillates at pi/3 radians per second.How far from equilibrium will the girl be in 4 seconds into the motion
Answer:
-0.75 m
Explanation:
The displacement of the girl is given by x = x₀cosωt where x₀ = maximum displacement of swing = 1.5 m, ω = angular frequency = π/3 rad/s and t = time of swing = 4 s
Substituting the values of the variables into the equation, we have
x = x₀cosωt
x = (1.5 m)cos(π/3 rad/s × 4 s)
x = (1.5 m)cos(2π/3)
x = (1.5 m)cos120°
x = 1.5 m × -0.5
x = -0.75 m
So, the girl is 0.75 m to the left of the equilibrium position 4 seconds into the motion.
can someone please help
The answer is B. Mono and polyunsaturated fats because the other two are really harmful and they are not healthy whatsoever.
A cable car is being pulled up a mountain at 7.5 meters per second. Usually, the car takes 120 seconds to move all the way up the mountain. If its velocity stays constant, how much time will it take the cable car to move 39 meters?
Answer:
5.2 s
Explanation:
From the question given above, the following data were obtained:
Velocity = 7.5 m/s
Displacement = 39 m up
Time =?
The time taken for the cable cab to get to 39 m can be obtained as follow:
Velocity = Displacement / Time
7.5 = 39 / time
Cross multiply
7.5 × time = 39
Divide both side by 7.5
Time = 39 / 7.5
Time = 5.2 s
Thus, the time taken for the cable cab to get to 39 m up is 5.2 s
Seeing these new artifically designed creatures at home, as the result of breeding, he coined the term ____ ______ to explain the variation of species around the islands and (by extension of his theory) also around the world.
Answer: Artificial Selection
Explanation: Artificial Selection is described as the identification of desirable traits in both plants and animals, then enhance them, so that those traits can be manifested in future generations.
This is the scope behind cross breeding of plants and animals and this have largely been used in agricultural sector to improve input (such as disease-resistant seeds) and other biotechnological settings.
Darwin's described artificial selection as the human form of natural selection.
is retractable measuring tape a simple machine?
Answer:
A simple machine is a device that multiply an applied force by the use of the mechanical advantage built into the machine. Therefore, a simple machine changes the direction in which the applied force acts or the magnitude of the applied force, or both in order to do work
A retractable measuring tape is a device used for length measurement such that the direction of the applied force is reversed during retraction, while the magnitude of the output force is constant and dependent on the coil in the measuring
Therefore, the measuring tape does not have a constant mechanical advantage or act as a force multiplier, and therefore;
It is not a simple machine
Explanation:
A householder has a 10.8 kW electric shower installed in the bathroom. Calculate the current drawn from the mains electricity supply by the shower.
Answer:
90 A
Explanation:
Applying,
P = VI.............. Equation 1
Where P = Power, V = Supply voltage, I = current.
Make I the subject of the equation
I = P/V.............. Equation 2
From the question,
Assuming the Voltage of the main electric supply is 120 V
Given: P = 10.8 kW = 10800 W, V = 120 V (household voltage)
Substitute these values into equation 2
I = 10800/120
I = 90 A
A force of 30.0 N is applied to a 3.00 kg object for 3.00 seconds. Calculate the velocity experienced by the object.
Answer:
Explanation:
F = ma and
[tex]a=\frac{v}{t}[/tex]
We have F, we have m, but in order to solve for v, we need a.
30.0 = 3.00a so
a = 10.0 m/s/s. Plug that in for a in the second equation and solve for v:
[tex]10.0=\frac{v}{3.00}[/tex] so
v = 10.0(3.00) so
v = 30.0 m/s
Một dây dẫn mảnh được uốn thành một cung tròn bán kính 10cm, góc ở tâm bằng 1200, đặt trong không khí. Trong dây dẫn có dòng điện cường độ 30A chạy qua. Độ lớn của cảm ứng từ tại tâm của cung tròn là bao nhiêu ?
Answer:
Diana and that
Explanation:
muyayyano
A 1,000 kg car is travelling at 6.5 m/s to the North. A 3,500 kg truck is travelling South at the same velocity. What is the total momentum of the two vehicles (don’t forget to assign a NEGATIVE velocity to one of the vehicles, because they are travelling in opposite directions
please help asap
Answer:
Total momentum of both is 16250 kgm/s
need help please... thank u
Answer:
the answer from my side is both vertical and horizontal
Answer:
Entirely horizontal
Explanation:
The ball begins the movement with horizontal and vertical velocity, but it is subject to the gravity acceleration, that will break the movement. When it achieves the top of the path, is when the vertical velocity go to 0 and begin to grow in the opposite direction, so in the very top of the path, the velocity is entirely horizontal
The vine has a fixed end, so Tarzan's path is circular. So the vine must not only support Tarzan's weight (or some component of it) but must also provide centripetal force to curve Tarzan's velocity. At Tarzan's lowest point, this can be expressed as:_________.
Answer: hello your question lacks some data attached below is the missing data
answer : T - mg = ma[tex]_{c}[/tex]
Explanation:
Given that the vine has a fixed end and Tarzan's path is circular
At Tarzans lowest point the point can be expressed as shown below.
It can be expressed as : T - mg = ma[tex]_{c}[/tex]
At what point will the electric field of a charged object be strongest?
A where the electric field lines are perpendicular to the equipotential line
B. where the electric field lines are farthest apart
C. where the electric field lines are closest together
D. where the electric field lines are parallel to the equipotential line
Answer:
The answer is C because they have to be close to be able to interact
Answer:
C. where the electric field lines are closest together
Explanation:
3.
The mass of a regulation tennis ball is 57 g. Typically during a serve the ball is in contact with the tennis racket for 30 ms. If the serve
was measured at 73.14 m/s what impulse was exerted on the tennis ball?
5.5 kg. m/s
7.8 kgm/s
2.3 kg. m/s
4.2 kg. m/s
How much force is required (in Newtons) to accelerate a 12-kg bicycle, along with its 50-kg rider, at 2 m/s2?
Give your answer as a number.
Answer:
F = 124 N
Explanation:
Given that,
The mass of bicycle and the rider, m = 12 kg + 50 kg = 62 kg
Acceleration of system, a = 2 m/s²
We need to find the force required to accelerate the system. We know that,
Net force, F = ma
Put all the values,
F = 62 kg × 2 m/s²
F = 124 N
So, the required force is equal to 124 N.
Which of the following is an elastic collision?
A.
A wad of gum sticking to a window
B.
Two cars colliding and sticking together
C.
A vase falling to the floor and shattering
D.
A tennis racquet hitting a ball
Answer: D
Explanation:
An elastic collision is a collision in which there is no net loss in kinetic energy in the system as a result of the collision. Both momentum and kinetic energy are conserved quantities in elastic collisions. Suppose two similar trolleys are traveling toward each other with equal speed.
The flow chart shows the life cycle of a star. Was this star smaller than our sun, about the same or bigger than our sun?
1. Bigger
2. About the same
3. Smaller
The star is bigger than our sun. The correct option is 1.
The flow chart of the life cycle of a star indicates that the star starts as a nebula, which is a cloud of gas and dust. The nebula can collapse due to gravitational forces and form a protostar. The protostar can then continue to contract and heat up until it reaches a temperature and density at which nuclear fusion can occur, leading to the star entering the main sequence phase.
The size of a star is determined by its mass, and the more massive a star is, the bigger it will be. Based on this information, we can infer that if a star follows the life cycle shown in the flow chart, starting from a nebula and eventually reaching the main sequence, it must be at least as massive as our sun or even more massive, since only stars with sufficient mass can become main sequence stars.
To learn about the heliocentric model of the Solar System click:
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