Calculate the maximum kinetic energy of photoelectrons emitted from this plate when light of wavelength (λ) 520nm is directed at the metal surface.Work function (Ф) of the plate = 1.1 × 10⁻¹⁹ J
Planck's constant (h) = 6.63 × 10⁻³⁴ Js
Frequency (f) = c ÷ λ
c = speed light in vacuum = 3.00 × 10⁸ms⁻¹
Ekmax = hf - Φ
Wavelength must be in metres, so it'll be 590×10⁻⁹
I've worked this out and gotten two different answers so I thought I'd check to see which one is right.
Answers
Put that into the equations:
f = c/λ = 3.0 x10^8/5.2 ×10^-7 = 5.77 x10^14 (3 s.f.)
(5.77 x10^14) x (6.63 x10^-34) - (1.1 x10^-19) =
2.73 x10^-19 J
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b. potentiometer
c. voltmeter
d. galvonmeter
e. batterymeter
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The device used to measure a potential difference in a circuit is called a voltmeter. The correct option is c.
What is a voltmeter?
The tool used to measure the potential difference between two locations in an electric circuit is called a voltmeter. A voltage meter usually referred to as a voltmeter, is a device that measures the voltage, or potential difference, between two points in an electrical or electronic circuit.
Both of these devices are employed in electric circuits, however, the voltmeter is primarily used to measure the voltage or emf across two points in an electric circuit, whilst the ammeter is mostly used to measure the flow of current.
Depending on the measurement, voltmeters are divided into two categories: DC voltmeters and AC voltmeters.
Therefore, the correct option is c. voltmeter.
To learn more about voltmeter, refer to the link:
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Answer:
High Amplitude
Explanation:
If the light from Star X is brighter than the same type of light from Star Y, you know that the light you see from Star X has a higher amplitude.
Denise wears an extremely bright safety yellow sweatshirt when she cycles to the gym after dark. The sweatshirt's brightness reflects the high amplitude of the light it reflects.
Final answer:
The brightness of Denise's sweatshirt while cycling after dark reflects the intensity of light it reflects. The color yellow is perceived when an object reflects red and green light and absorbs blue light. The brightness can also be enhanced by the reflection efficiency of the sweatshirt's material and its fluorescence properties.
Explanation:
Denise's extremely bright safety yellow sweatshirt when she cycles to the gym after dark, reflects the intensity of the light it reflects. The color of an object is determined by the wavelengths of light that the object reflects. A yellow object appears yellow because it reflects yellow light and absorbs other colors. Reflection of light is the fundamental concept behind the brightness of the sweatshirt.
The yellow sweatshirt absorbs blue light and reflects red and green light, which our eyes perceive as yellow. The intensity or brightness of the sweatshirt is a function of how much light it reflects back. Another important factor is the reflection efficiency of the sweatshirt's material. Some materials are better at reflecting light than others which can enhance brightness.
Also, the fluorescence property of some safety colors makes them emit more light than they receive which enhances their brightness, this is especially useful in low light conditions, such as cycling after dark.
Learn more about Light Reflection
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Answer: The slope of a line on a distance-time graph is- speed of the object.
The slope of a line on a graph refers to rate of change of variable that is presented on Y axis with respect to the variable that is presented on X axis.
For a distance time graph, distance is presented on Y axis and time on the X axis.
As we know that
Therefore, the slope of a line on a distance-time graph represents speed of the object.
Slope of any given curve is defined as
Rate of change in quantity on Y axis with respect to the quantity on x axis.
Here on Y axis if we plot distance and on X axis if time is plotted then
Slope = [tex] \frac{ds}{dt}[/tex}
above expression is rate of change in distance with time which shows apped of object