Answer:
Explanation:
Relation between power and illumination and distance is as follows
[tex]I = \frac{P}{R^2}[/tex]
For first case
[tex]3600 = \frac{60}{d^2}[/tex]
for second case
[tex]I = \frac{120}{(0.5d)^2}[/tex]
[tex]\frac{I}{3600} = \frac{d^2}{60} \times \frac{120}{.25d^2}[/tex]
I = 3600 x 8
= 28800 lux .
Final answer:
The illuminance on a surface from a 120-Watt bulb at half the distance of an initial setup with a 60-Watt bulb would be 28800 lux, due to the Inverse Square Law for Light and doubling of the bulb wattage.
Explanation:
The question is asking us to determine the illuminance on a surface from a 120-Watt bulb at half the distance of a previous setup with a 60-Watt bulb, which originally had an illuminance of 3600 lux. According to the Inverse Square Law for Light, illuminance changes with the inverse square of the distance. If the distance is halved (d/2), the illuminance increases by a factor of 4 (since (1/0.5)2 = 4). However, since we are also doubling the wattage of the bulb from 60-Watt to 120-Watt, and assuming that the bulb’s efficiency (lumens per Watt) stays the same, the illuminance would double again. Therefore, the new illuminance would be 3600 lux x 4 (due to distance) x 2 (due to wattage), equaling 28800 lux.
In which direction is the magnetic force acting in the charge?
Answer:
"Right Hand
Right Hand Rule: Magnetic fields exert forces on moving charges. This force is one of the most basic known. The direction of the magnetic force on a moving charge is perpendicular to the plane formed by v and B and follows right hand rule–1 (RHR-1) "
Explanation:
Answer:
The direction of the magnetic force acting on a moving electric charge in a magnetic field is perpendicular to the direction of motion. A magnetic force is exerted on an electric charge moving through a uniform magnetic field. An electric charge moving parallel to a magnetic field experiences a magnetic force.
Explanation:
3. A 0.35 kg puck slides across the ice with an average force of friction of 0.15 N acting on it. It slides 82 m before coming to rest. How much work was done on the puck?
Answer:
Work done is 12.3 J
Explanation:
We have,
Mass of puck, m = 0.35 kg
Force of friction acting on the puck when it slides is 0.15 N
Distance travelled by the puck is 82 m.
It is required to find the work done on the puck. Finally the puck comes to rest and the force of friction is acting on it. It means the applied force is 0.15 N. Work done is given by
[tex]W=Fd\\\\W=0.15\times 82\\\\W=12.3\ J[/tex]
The work done on the puck is 12.3 J.
An object with a mass of 7 kg accelerates 5 m/s2 when an unknown force is applied to it. What is the unknown force?
Answer:
35 N
Explanation:
Force, F = ma where m = mass = 7 kg and a = acceleration = 5 m/s².
So, F = ma = 7 kg × 5 m/s² = 35 N
Final answer:
To find the unknown force applied to an object with a mass of 7 kg accelerating at 5 m/s², use the formula F = ma to calculate it as 35 N.
Explanation:
The unknown force applied to the object with a mass of 7 kg can be calculated using the formula F = ma.
Given mass (m) = 7 kg and acceleration (a) = 5 m/s²
Substitute the values into the formula: F = (7 kg) (5 m/s²) = 35 N
Therefore, the unknown force applied to the object is 35 Newtons.
How much force is required to produce a torque of 100 Nm if the force is applied at an angle of 40 at a distance of 25 cm from the pivot?
Answer:
Force, F = 622.28 N
Explanation:
It is given that,
Torque, [tex]\tau=100\ N-m[/tex]
Angle between force and displacement, [tex]\theta=40^{\circ}[/tex]
Distance, d = 25 cm = 0.25 m
We need to find the force required to produce the torque. Torque produced by an object is given by :
[tex]\tau=Fd\sin\theta[/tex]
F is force required to produce torque
[tex]F=\dfrac{\tau}{d\sin\theta}\\\\F=\dfrac{100}{0.25\times \sin(40)}\\\\F=622.28\ N[/tex]
So, applied force is 622.28 N.
Which describes a relationship when calculating the energy of a photon? The energy of the photon is directly proportional to frequency. The energy of the photon is inversely proportional to frequency. As the energy of the photon increases, Planck’s constant increases. As the energy of the photon increases, Planck’s constant decreases.
Answer:
The energy of a photon is directly proportional to it's frequency
Answer:
B. The energy of the photon is directly proportional to frequency.
Explanation:
An atom of 6/2 He decays by beta decay. What atom is left after decay
Answer:
6/3 LI
Explanation:
You have a tungsten sphere (emissivity ε = 0.35) of radius 25 cm at a temperature of 25°C. If the sphere is enclosed in a room whose walls are kept at -5°C, what is the net flow rate of energy out of the sphere?
The net rate of energy flow from the tungsten sphere can be calculated using the modified Stefan-Boltzmann equation, taking into account the sphere's emissivity, surface area and temperature, as well as the temperature of the surroundings. After calculating, we have the net rate of heat transfer.
Explanation:The net flow rate of energy from an object, in this case a tungsten sphere, can be calculated using the modified Stefan-Boltzmann equation which is suitable for net rate of heat transfer by radiation. The formula used is Qnet = σeA(T₁⁴ - T₂⁴), where σ is the Stefan-Boltzmann constant (5.67 × 10⁻⁸ J/s.m².K⁴), e is the emissivity (0.35 for tungsten), A is the surface area of the sphere (πr² with r being the radius of the sphere), and T₁ and T₂ are the temperatures of the sphere and the surroundings respectively, converted to Kelvin.
First, we convert the Celsius temperatures to Kelvin by adding 273.15 to each temperature, making T₁ = 298.15 K and T₂ = 268.15 K. Then, finding the surface area, we get A = 4πr² = 4.90 m² with r = 0.25 m. Substituting these values into the equation gives us Qnet = (5.67 × 10⁻⁸ J/s.m².K⁴)(0.35)(4.90 m²)[(298.15 K)⁴ - (268.15 K)⁴] which, when calculated, gives the net rate of heat transfer by radiation from the tungsten sphere.
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Final answer:
The net flow rate of energy from a tungsten sphere in a cooler room can be calculated using the Stefan-Boltzmann law; accounting for emissivity, surface area, and the difference in the fourth powers of the absolute temperatures of the sphere and its surroundings.
Explanation:
The student's question regarding the net flow rate of energy out of a tungsten sphere enclosed in a room with cooler walls can be answered using the Stefan-Boltzmann law for thermal radiation which states that the power radiated from an object is proportional to its emissivity (e), the Stefan-Boltzmann constant (σ), the surface area of the object (A), and the fourth power of its absolute temperature (T) in kelvins. For our purposes, the net power radiated is the difference in power radiated by the sphere and the power absorbed from the surroundings. To find the surface area (A) of the sphere we use the formula 4πr2 where r is the radius of the sphere. Then, we transform the temperatures from Celsius to Kelvins and plug our values into the equation P = eσA(T4 - T04) to find the net flow rate of energy out of the sphere.
as the angle of incidence of light increases, what happens to the angle of refraction?
Answer:
it increases too as it bend away from the normal line
A 1400 kg vehicle travelling at 22 m/s slows at a constant rate to 4.5 m/s in 6.75 s. What was the net force acting on the car during this time?
Answer:
Net force = 3640 N
Explanation:
From first equation of motion
V = U + at
4.5 = 22 + 6.75a
( 4.5-22) ÷ 6.75 = a
acceleration (a) = -2.6m/s^2 ( negative sign shows deceleration, but actual acceleration is 2.6)
But Force = mass × acceleration
Force = 1400 × 2.6
Force = 3640 N
(ii)
Calculate the amount of energy required to melt 15 kg of ice at 0 °C.
Specific latent heat of fusion of ice = 3.4 x 105 J/kg.
Energy =
Answer:
uekdjdbrjrnkfkdkfkff
Explanation:
E=mc(tetha)
=15(3.4x105)(0)
=0joules
How can the image be described? Check all that apply. (Interpreting Ray Diagrams)
Answer:
the object is kept away from the focus of a convex lens. it form a real but inverted image of the object on the opposite side of the lens.
Which planets have craters?
Answer:Mercury, Venus, Earth and Mars.
Explanation: The surfaces of asteroids and the rocky, ice covered moons of the outer gas planets are cratered as well.
Rank these objects on the basis of their wavelength. (largest to smallest)person v=4.5m/selectron v=0.01cred light v=cproton v=0.01ccar v=27m/sbaseball v=41m/s
Answer:
red light > electron > proton > baseball > person > car
Explanation:
To calculate the wavelength associated to each object, you use the Broglie's relation:
[tex]\lambda=\frac{h}{mv}\\\\[/tex]
h: Planck,s constant = 6.62*10^-34 Js
m: mass
v: velocity
For each object you use an average values of its mass.
person:
mass = 80kg
[tex]\lambda=\frac{6.62*10^{-34}Js}{(80kg)(4.5m/s)}=1.83*10^{-36}m[/tex]
electron:
mass = 9.1*10^{-31}kg
[tex]\lambda=\frac{6.62*10^{-34}Js}{(9.1*10^{-31}kg)(0.01c)}\\\\\lambda=\frac{6.62*10^{-34}Js}{(9.1*10^{-31}kg)(0.01(3*10^{8}m/s))}\\\\\lambda=2.42*10^{-10}m[/tex]
red light:
In this case you use the following formula:
[tex]\lambda=\frac{c}{f}=\frac{3*10^8m/s}{4.3*10^{14}Hz}=6.97*10^{-7}m\approx700nm[/tex]
proton:
mass = 1.67*10^{-27}kg
[tex]\lambda=\frac{6.62*10^{-34}Js}{(1.67*10^{-27}kg)(0.01(3*10^8m/s))}\\\\\lambda=1.32*10^{-13}m[/tex]
car:
mass = 1500kg
[tex]\lambda=\frac{6.62*10^{-34}Js}{(1500kg)(27m/s)}=1.63*10^{-38}m[/tex]
baseball:
mass = 0.145kg
[tex]\lambda=\frac{6.62*10^{-34}Js}{(0.145kg)(41m/s)}\\\\\lambda=1.11*10^{-34}m[/tex]
hence, by comparing the wavelengths of the objects you have:
red light > electron > proton > baseball > person > car
Timmy and Sarah go for a hike. they hike 5 miles in three hours and 15 minutes. what is the average speed to the nearest 10th of a mile. (Hint - you need to convert minutes to hours)
The average speed is 1.54 miles per hour.
As we know that,
Average speed [tex]=\frac{Distance}{time}[/tex]
Given that Timmy and Sarah travel 5 miles in three hours and 15 minutes.
Time [tex]=3+\frac{15}{60} =\frac{13}{4}hours[/tex]
Average speed [tex]=5\div \frac{13}{4} =5*\frac{4}{13}=1.54 miles/hour[/tex]
Thus, The average speed is 1.54 miles per hour.
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1) My 14V car battery could be used to charge my laptop, but I need to use an inverter to first convert it to a standard 120V. Then my laptop charge cord has a resistor inside which ensures that 1.6A of current flow through to the laptop. What is the resistance in the charge cord?
2) My laptop charge cord actually has another inverter inside tat converts the electricity to 19.5V and 3.33A. What is the resistance in the cord that accomplishes this?
Answer:
1) Charge chord resistance is 75 Ω
2) Charge chord resistance is 6.33 Ω
Explanation:
1) To answer the question, we note that the the formula voltage is found as follows;
V = IR
Therefore,
[tex]R = \frac{V}{I} = \frac{120}{1.6} = 75 \, \Omega[/tex]
2) Where the voltage, V = 19.5 V and the current, I = 3.33 A, we have;
Initial resistance R₁ = 19.5 V/(3.33 A) = 5.86 Ω
However, to reduce the current to 1.6 A, we have;
[tex]R_T = \frac{19.5}{1.6} = 12.1875 \ \Omega[/tex]
Therefore, where the resistance is found by the sum of the total resistance we have;
[tex]R_T[/tex] = R₁ + Charge chord resistance
∴ 12.1875 = 5.86 + Charge chord resistance
Hence, charge chord resistance = 6.33 Ω
(1) The resistance in the charge cord at the given standard voltage is 75 ohms.
(2) The resistance in the cord that accomplishes the given voltage and current is 6.33 ohms.
The given parameters;
voltage of the car battery, V = 14 Vstandard voltage, = 120 Vcurrent in the laptop charger, I = 1.6 AThe resistance in the charge cord at the given standard voltage is calculated as follows;
[tex]V = IR\\\\R = \frac{V}{I} \\\\R = \frac{120}{1.6} \\\\R = 75 \ ohms[/tex]
The initial resistance when the voltage is 19.5 V and current is 3.33 A;
[tex]R = \frac{V}{I} \\\\R = \frac{19.5}{3.33} \\\\R = 5.86 \ ohms[/tex]
The total resistance when the current in cord is calculated as;
[tex]R = \frac{V}{I} \\\\R = \frac{19.5}{1.6} \\\\R = 12.19 \ ohms[/tex]
The internal resistance is calculated as;
[tex]r = 12.19 - 5.86\\\\r = 6.33 \ ohms[/tex]
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A 0.5 kg ball is at the top of a ramp which is 8 meters high. How much
Vinetic energy does the ball have at the bottom of the ramp? (round the
answer to the tenths place)
Answer:
same as the potential energy possessed at top
= 0.5×9.8×8
= 39.2 joules
Answer: The answer is 40 J.
Explanation: I did it just now.
Amphibians live part of their lives like:___
A.Mammals
B.Fish
C.Birds
A woman is pushing a 38.7kg lawnmower initially at rest with a 68.7N forward force against friction. The lawnmower speeds up to 1.44m/s in 3.81s. How much force does friction evert on the mower
Answer:
expected acceleration= 68.7/38.7=1.77 m/s^2
witnessed acceleration = 1.44/3.81 = 0.37 m/s^2
difference = 1.4m/s^2
so friction = 38.7× 1.4= 54.18 N
The magnitude of force does friction evert on the mower is 54.07 N.
What is speed?Speed is distance travelled by the object per unit time. Due to having no direction and only having magnitude, speed is a scalar quantity With SI unit meter/second.
Given parameters:
Mass of the lawnmower: M = 38.7 kg.
Force applied on it: F = 68.7 N.
Final speed of the lawnmower: v = 1.44 m/s.
Time taken: t = 3.81 s.
Then, acceleration of the lawnmower: a = increase in speed/time
= 1.44/3.81 m/s² = 0.38 m/s².
Hence, resisting friction force = applied force - ma
= 68.7 N - 38.7 × 0.38 N
= 54.07 N.
Hence, the magnitude of force does friction evert on the mower is 54.07 N.
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A wave with a frequency of 60.0 Hz travels through rubber with a wavelength of .90 m. What is the speed of this wave?
Answer:
Speed of wave 54 ms⁻¹.
Explanation:
Given data:
Frequency of wave = 60 Hz
Wavelength of wave = 0.90 m
Speed = ?
Solution:
Formula
speed = wavelength × frequency
Now we will put the values in formula.
v = f × λ
Hz = s⁻¹
v = 60 s⁻¹ × 0.90 m
v = 54 m s⁻¹
A wave with a frequency of 60 Hz and a wavelength of 0.90 m through rubber travels at a speed of 54 m/s.
Explanation:The speed of a wave can be calculated by the formula: Speed = Frequency * Wavelength. Given that the frequency is 60.0 Hz and the wavelength is 0.90 m, we can substitute these values into the formula. Therefore, the speed of the wave is 60.0 Hz * 0.90 m = 54 m/s. This means that a wave with a frequency of 60 Hz and a wavelength of 0.90 m travels through rubber at a speed of 54 m/s.
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Why is it a good idea to discuss gravity and fluid flows when learning about electricity?
Answer:
The flow of fluid molecules in fluid mechanics is synonymous to the flow of electrons in electricity.
Explanation:
The flow of fluid molecules in fluid mechanics is synonymous to the flow of electrons in electricity. Water, when it is falling by the force of gravity, can be used to turn turbines and generators that produce electricity.
A turbine converts the kinetic energy of falling water into mechanical energy. Then a generator converts the mechanical energy from the turbine into electrical energy. Hydroelectric power plants are the most efficient means of producing electric energy.
Discussing gravity and fluid flows is beneficial when learning about electricity due to the analogies between these phenomena, which aid in understanding the behavior of electric charges and circuits. These comparisons help visualize electrical concepts and deepen comprehension of various electrical phenomena and technologies.
Discussing gravity and fluid flows when learning about electricity is crucial due to the similarities in the concepts governing all these phenomena. For instance, electricity is often taught through the analogy of water flow in pipes, where electric current, voltage, and resistance are likened to the flow rate, pressure difference, and pipe size in fluid dynamics. This analogy helps students visualize and understand how electric charges behave in circuits, just as water flows through a system under the influence of gravity. Moreover, the concept of gravitational potential energy in physics is analogous to electric potential energy in electromagnetism, where masses and charges experience forces due to their respective fields. Understanding these analogies deeply enriches the comprehension of electrical phenomena and leads to insights into the behavior of electricity in various mediums, such as solids, liquids, and gases.
Examples such as lightning, the formation of bluish crust on car battery terminals, and the need for electrolytes in sports drinks can be understood better by studying the flow of charged particles. These particles, like fluid in the presence of a gravitational field, respond to electric fields by moving from areas of high potential to low potential, analogous to water flowing downward due to gravity. This comparison between electric and gravitational fields lays a solid foundation for exploring more complex electrical behaviors and technologies.
What is the total mechanical energy of a 200 kg roller coaster moving with a velocity of 16 m/s at a height of 18 m above the ground?
Mechanical Energy = PE + KE
PE: mgh = 200 x 9.8 x 18 = 35280
PE: 35280 Joules
KE: 1/2mv^2 = 1/2 x 200 x 16^2 = 25600
KE: 25600 Joules
ME: 35280 + 25600
ME: 60,880J
A red car passes a blue car. Which is true?
A.
The blue car must be parked.
B.
The red car must be moving backwards.
C.
The blue car must be moving slowly.
D.
The red car is moving faster than the blue car.
Answer:
D
Explanation:
A man is 6ft tall. What is the smallest size plane mirror he can use to see his entire image.
The smallest size plane mirror he can use is 3 feet tall, ensuring he can see his entire image reflected in the mirror
To see his entire image in a plane mirror, the mirror needs to be at least as tall as the man's height. However, since only half of his height is required for the mirror, the smallest size plane mirror he can use is half his height.
Given that the man is 6 feet tall, the smallest size plane mirror he can use to see his entire image would be [tex]\( \frac{6}{2} = 3 \)[/tex] feet tall. Therefore, the smallest size plane mirror he can use is 3 feet tall.
A series circuit consists of four resistors connected in series with values of 1.1,
11, 110, and 1100 ohms. What is the equivalent resistance of the circuit?
Answer:
Explanation:
hope this provides you with some clarity :)
To find the equivalent resistance of a series circuit consisting of resistors with values 1.1 ohms, 11 ohms, 110 ohms, and 1100 ohms, simply add the values together, resulting in an equivalent resistance of 1222.1 ohms.
The question involves calculating the equivalent resistance of a series circuit containing four resistors with the specified values of 1.1 ohms, 11 ohms, 110 ohms, and 1100 ohms. In a series circuit, the total or equivalent resistance can be found by simply adding up all the resistance values of the individual resistors.
To find the equivalent resistance of the circuit, we add the values of the resistors:
1.1 ohms11 ohms110 ohms1100 ohmsThe sum of these values gives us the total resistance:
1.1 + 11 + 110 + 1100 = 1222.1 ohms.
Therefore, the equivalent resistance of the series circuit is 1222.1 ohms.
If you drop something from low height is it faster
Faster to hit the ground because if so yes?
An open organ pipe is 2.46 m long, and the speed of the air in the pipe is 345 m/s.
a. What is the fundamental frequency of this pipe?
Answer:
Fundamental frequency is 70.12 m
Explanation:
For an open organ pipe, the fundamental frequency is given by :
[tex]f=\dfrac{nv}{2l}[/tex]
n = 1 for fundamental frequency
v is speed of sound in air, v = 345 m/s
l is length of open organ pipe, l = 2.46 m
Substituting values in above formula. So,
[tex]f=\dfrac{1\times 345}{2\times 2.46}\\\\f=70.12\ Hz[/tex]
So, the fundamental frequency of this pipe is 70.12 m.
Final answer:
The fundamental frequency of a 2.46 m long open organ pipe, with air speed 345 m/s, is approximately 70.12 Hz.
Explanation:
To find the fundamental frequency of an open organ pipe, we can use the formula for the fundamental frequency of a pipe that is open at both ends, which is f1 = v / (2*L), where f1 is the fundamental frequency, v is the speed of sound in the pipe, and L is the length of the pipe.
In this case, the organ pipe is 2.46 meters long, and the speed of the air in the pipe is given as 345 meters per second. Plugging these values into the formula, we get:
f1 = 345 m/s / (2 * 2.46 m) = 345 m/s / 4.92 m = 70.12 Hz
Therefore, the fundamental frequency of this 2.46 m long open organ pipe is approximately 70.12 Hz.
This a physics problem please solve the elastic collision problem use guess if you can if you can’t it’s fine
I will use my guess because I can. Unless you're the same person just spamming their question but if not, don't worry about it. they will crash at 5 m/s.
Final answer:
To analyze an elastic collision, one should use the momentum and kinetic energy conservation equations, simplifying them if one object is initially at rest. Inelastic collisions involve the conservation of momentum only and require experimental measures to determine energy dissipation.
Explanation:
An elastic collision is a type of collision where both momentum and kinetic energy are conserved. To solve a problem involving an elastic collision, one must use two independent equations: the conservation of momentum equation and the conservation of kinetic energy equation. If one of the objects is initially at rest, as stated in the question, the equations become simpler. We can set the initial velocity of the second object to zero, and then combine the equations algebraically to solve for the final velocities of both objects.
In the case of an inelastic collision, only momentum is conserved, and some kinetic energy is transformed into other forms of energy, such as heat or sound. To analyze changes in kinetic energy for an inelastic collision, one could modify an experiment to measure velocities before and after the collision and then calculate the kinetic energy to determine the fraction of mechanical energy dissipated.
In summary, analyzing an elastic collision typically involves mathematical calculations of velocities and kinetic energy, while an inelastic collision would be explored through experiments and calculations focusing on energy dissipation. If making graphical representations, one would plot momentum and kinetic energy before and after the collision to verify these relationships.
How much power can a motor output if it does 25 J of work in 1 s? *
Answer:
25 W
Explanation:
Power: This can be defined as the rate at which work is done. The S.I unit of power is Watt (W).
The expression of power is given as
Power = work output/time
P = W/t................ Equation 1
Given: W = 25 J. t = 1s
Substitute into equation 1
P = 25/1
P = 25 W
Hence the output power of the motor is 25 W
Answer:
The power is 25 W
Explanation:
Given;
work done by motor output. E = 25 J
Time taken to complete this task, t = 1 s
Power is the amount of work done per unit time or energy per unit time.
The amount of power developed by the motor, can be calculated as follows using the formula below;
[tex]Power = \frac{Energy}{time} = \frac{25}{1} = 25 \ W[/tex]
Therefore, the amount of power developed by the motor in the given time is 25 W.
Figure 15-3 In Figure 15-3, which gas makes up the greatest percentage of Earth's atmosphere?
Answer:
Nitrogen
Explanation:
What is potential energy?
Energy released
Energy stored
Moving Energy