Answer:
a) [tex] v = 2.36 \cdot 10^{7} m/s [/tex]
b) [tex] B = 3.80 \cdot 10^{-4} T [/tex]
c) [tex] f = 1.06 \cdot 10^{7} Hz [/tex]
d) [tex] T = 9.43 \cdot 10^{-8} s [/tex]
Explanation:
a) We can find the electron's speed by knowing the kinetic energy:
[tex] K = \frac{1}{2}mv^{2} [/tex]
Where:
K: is the kinetic energy = 1.59 keV
m: is the electron's mass = 9.11x10⁻³¹ kg
v: is the speed =?
[tex] v = \sqrt{\frac{2K}{m}} = \sqrt{\frac{2*1.59 \cdot 10^{3} eV*\frac{1.602 \cdot 10^{-19} J}{1 eV}}{9.11 \cdot 10^{-31} kg}} = 2.36 \cdot 10^{7} m/s [/tex]
b) The electron's speed can be found by using Lorentz's equation:
[tex] F = q(v\times B) = qvBsin(\theta) [/tex] (1)
Where:
F: is the magnetic force
q: is the electron's charge = 1.6x10⁻¹⁹ C
θ: is the angle between the speed of the electron and the magnetic field = 90°
The magnetic force is also equal to:
[tex] F = ma_{c} = m\frac{v^{2}}{r} [/tex] (2)
By equating equation (2) with (1) and by solving for B, we have:
[tex] B = \frac{mv}{rq} = \frac{9.11 \cdot 10^{-31} kg*2.36 \cdot 10^{7} m/s}{0.354 m*1.6 \cdot 10^{-19} C} = 3.80 \cdot 10^{-4} T [/tex]
c) The circling frequency is:
[tex] f = \frac{1}{T} = \frac{\omega}{2\pi} = \frac{v}{2\pi r} [/tex]
Where:
T: is the period = 2π/ω
ω: is the angular speed = v/r
[tex] f = \frac{v}{2\pi r} = \frac{2.36 \cdot 10^{7} m/s}{2\pi*0.354 m} = 1.06 \cdot 10^{7} Hz [/tex]
d) The period of the motion is:
[tex] T = \frac{1}{f} = \frac{1}{1.06 \cdot 10^{7} Hz} = 9.43 \cdot 10^{-8} s [/tex]
I hope it helps you!
After the water has boiled, the temperature of the water decreases by 22 °C.
The mass of water in the kettle is 0.50 kg.
The specific heat capacity of water is 4200 J/kg °C.
Calculate the energy transferred to the surroundings from the
water.
Energy=
Explanation:
Use the formula:
[tex] e = mc \delta \theta[/tex]
e is the energy released,
m is the mass of water,
c is the specific heat capacity,
δθ is the change in temperature ( 100 - 22)
A string with a length of 0.75 m is fixed at both ends. (a) What is the longest possible wavelength for the traveling waves that can interfere to form a standing wave on this string? (b) If waves travel with a speed of 130 m/s on this string, what is the frequency associated with this longest wavelength?
Answer:
a) Longest wavelength is: [tex]\lambda_{1}=2*0.75=1.5\: m[/tex]
b) The frequency associated with this longest wavelength is: [tex]f=86.7\: Hz[/tex]
Explanation:
a)
The wavelength equation of a standing wave is given by:
[tex]\lambda_{n}=\frac{2}{n}L[/tex]
Where:
L is the length of the stringn is a natural numberWe use n=1 to find the longest possible wavelength, so we will have:
[tex]\lambda_{1}=2L[/tex]
[tex]\lambda_{1}=2*0.75=1.5\: m[/tex]
b)
The speed of the wave is given by:
[tex]v=f\lambda[/tex]
So we just need to find the f (frequency).
[tex]f=\frac{v}{\lambda}[/tex]
[tex]f=\frac{130}{1.5}[/tex]
[tex]f=86.7\: Hz[/tex]
I hope it helps you!
A trumpeter plays at a sound level of 75dB. three equally loud trumpet players join in. what is the new sound level?
What is the speed of a wave with a period of 25 sec/cycle and a wavelength of 15 m/cycle?please help me !
(1) Expansion of concrete
A section of concrete which is 50 meters long experiences a temperature change from -10 Celsius to 46 degrees Celsius. What is the expansion of the concrete?
(2) Stainless steel
A rod of stainless steel (Austenitic) of mass 20 kg has 12057984 Joules of heat added to it. It’s initial temperature is 22 degrees Celsius. The original length is 1 meter.
a. What is the expansion of this rod?
b. Does it melt?
c. What is the final color?
(3) Mystery metal
A rod of some metal is measured to be .6 meters at room temperature (23 Celsius). It is then heated to 99 Celsius and then its length is measured to be .600664. Given the table of expansion coefficients below what type of metal is it? (all numbers in chart are multiplied by 10-6)
material expansion coefficient
silver 19
gold 14.2
indium 33
brass 18
bronze 17.5
Q1. Helmut rides 5km in 2h on his bike. His speed was *
a) 10km/h
b) 2.5km/h
c) 0.4km/h
d) 2.5km
Q2. A plane is travelling at 250km/h and must reach a target that is 3h 58min away. The distance to the target is. *
a) 1000km
b) 89500km
c) 62.5km
d) not enough information
Answer:
Speed of bike = 2.5 km/h
Distance travel = 1,000 km (Approx.)
Explanation:
Given:
Distance cover by Helmut = 5 km
Time taken = 2 hour
Find:
Speed of bike
Computation:
Speed = Distance / Time
Speed of bike = 5 / 2
Speed of bike = 2.5 km/h
Given:
Speed of plane = 250 km/h
time taken = 3 hr 58 min = 3.967 hr
Find:
Distance travel
Computation:
Distance = Speed x time
Distance travel = 250 x 3.967
Distance travel = 991.669
Distance travel = 1,000 km (Approx.)
Give me four reasons pluto is a cool planet / dwarf planet
On the Moon’s surface, lunar astronauts placed a corner reflector, off which a laser beam is periodically reflected. The distance to the Moon is calculated from the round-trip time. What percent correction is needed to account for the delay in time due to the slowing of light in Earth’s atmosphere? Assume the distance to the Moon is precisely 3.84×108 m , and Earth’s atmosphere (which varies in density with altitude) is equivalent to a layer 30.0 km thick with a constant index of refraction n = 1.000293.
Answer:
[tex]T_d=2.8*10^-^6\%[/tex]
Explanation:
From the question we are told that
Distance b/w Earth and the moon [tex]d_e=3.84×10^8 m[/tex]
Thickness of Earth's atmosphere[tex]d_t=30km[/tex]
Constant index of refraction [tex]n = 1.000293.[/tex]
Generally the equation for percentage of time delay [tex]T_d[/tex] is mathematically given as
[tex]T_d=\frac{d(n-1)}{rm}*100\%[/tex]
[tex]T_d=\frac{(35*10^3)(1.000293-1)()100)}{3.674*10^8} *\%[/tex]
[tex]T_d=2.8*10^-^6 \%[/tex]
Therefore the general percentage correction needed because of tym deley is given as
[tex]T_d=2.8*10^-^6\%[/tex]
Mu
wann-A
Very Short Answer Type Questions
1. Name the nutrients present in our food which give mainly energy to our body.
2. Name the nutrient which is needed for the growth and repair of our body. Proteins
3. Name the main carbohydrate which we eat in our food. I heat Rica maizes Pearl Potato
4. Which carbohydrate is present in wheat, rice and potatoes ? Plants
5. Name two foods each rich in (a) fats, and (b) starch. Batterheen
6. Name the major nutrients in our food.Combshed soles Fats Rooten mineral water Vitamin
7. Name the vitamin which is required for maintaining good eyesight Witamin A
8. Name the vitamin which keeps the teeth, gums and joints healthy, and helps fight diseases. 14
9. Name the vitamin which is necessary for the normal growth of bones and teeth Wermico
10. Which vitamin is produced in the human body when skin is exposed to sunlight ? uamu-D
11. Name the main vitamin present in (a) oranges, and (b) carrots. Worthing
12 Name an important mineral present in (a) apple, and (b) sea-fish.
13. Which mineral is needed to make haemoglobin present in our red blood cells.
14. In addition to calcium, which other mineral is needed for making bones and teeth ? (chum, Pha
15. Name a mineral which is needed for keeping bones and teeth healthy.
16. Which mineral is needed for the proper functioning of thyroid gland ?
17. Name two food materials which contain a lot of water. Fresh forest
18. Name the component of our food which helps prevent constipation. bulk oftend, wollte man
Vegetable
19. What is the other name of roughage? Dletary Abu
29Which component of food is mainly made of indigestible carbohydrate 'cellulose'?
21. The examples of carbohydrates are : sugar, cellulose, glucose and starch. Which of these carbohydrate
provides roughage in our food ?
22. Name two components of food which do not provide any nutrients.Cellulog
23. Fill in the following blank with a suitable word :
Iron is an important constituent of.........present in our blood. Hemoglobin
Short Answer Type Questions
24. What is the function of fats in our body? Name
A compressed spring launches a block up an incline. Which objects should be included within the system in order to make an energy analysis as easy as possible
Answer:
Block, incline, spring and gravity.
Explanation:
For us to have an energy analysis involving gravitational and spring potential energy, we will need to have a block with specific mass that is held at rest on a frictionless incline plane. Now, the block will compress the spring by a specific length from its equilibrium position and then the block is released to travel a distance right up the slope.
So basically, we will need Block, incline, spring and then gravity for it to move.
1. Which energy is stored in the bonds between atoms?
Answer:
Explanation: Energy, potential energy, is stored in the covalent bonds holding atoms together in the form of molecules. This is often called chemical energy.
1pt The process by which rock minerals are changed by natural processes into new substances is known as:
O A. erosion.
O B. chemical weathering.
O C. sedimentation.
O D. mechanical weathering.
The process by which rock minerals are changed by natural processes into new substances is known as chemical weathering. Option A is correct.
What is weathering?The breakdown or dissolution of rocks and minerals on the Earth's surface is referred to as weathering.
Weathering is the erosion or disintegration of rocks, building materials, etc., induced by chemical interactions dissolved in it rather than by mechanical processes.
Water, ice, acids, salts, plants, animals, and temperature variations are all weathering agents.
Chemical weathering is the process by which rock minerals are transformed into new compounds by natural processes.
Hence, option A is correct.
To learn more about weathering refer;
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what is the wavelength of a wave with the frequency of 330 Hz and a speed of 343 m/s
Answer:
The wavelength of a wave with the frequency of 330hz and a speed of 343m/s would be 1.04m
Explanation:
You can get the wavelength of a wave by dividing the speed of the wave by its frequency, which in this case would be:
343/300, which as a decimal number, it'd be 1.04.
I hope I helped you, and a "Brainliest" is always appreciated! ☺
Which sentence in the passage can be used to conclude that Eris is a dwarf planet and not a planet?
Erls takes about 557 Earth years to orbit the Sun. It has a mean surface temperature of about 40 Kelvin. It has a nearly spherical shape. It has
several other objects in its orbit, though
few are as massive as itself. Eris is too far away and small to be clearly visible from the Earth. Scientists
used its moon, Dysnomla, to measure it Qris is believed to be slightly more massive than Pluto. However, both of them are smaller than Earth's
Moon. Eris orbits the Sun directly, it is not a satellite of another planet or dwarf planet.
I
think
Answer:
is.......
it has several other objects in its original, though few are as massive as itself........
Answer:
my teachers have always taught me that a dwarf planet cannot have other objects in its orbit seeing that the gravitational force will make it collide with the planet or push it out of the orbit. hope it helps xx
how much work is done in accelerating a 2000 kg car from rest to a speed of 30 m/s?
A flag is waved 3.2 m above the surface of a flat pool of water. When viewed from under the water, what is the magnification of the flag? Let the indices of refraction nwater = 1.33 and nair = 1.00.
1.33
0.754
1
1.67
Answer:
1.33
Explanation:
For an optical instrument, the magnification ratio of the apparent diameter of the image to that of the object.
Mathematically, from the given information;
Magnification[tex]= \dfrac{n_{water}}{n_{air}}[/tex]
where;
[tex]n_{water} =1.33\\ \\ n_{air} = 1.00[/tex]
[tex]= \dfrac{1.33}{1.00} \\ \\= \mathbf{1.33}[/tex]
Ali is sitting on the chair, identify the forces acting on him.
A radial saw has a blade with a 9-in. radius. Suppose that the blade spins at 1000 rpm. (a) Find the angular speed of the blade in rad/min. Incorrect: Your answer is incorrect. webMathematica generated answer key rad/min (b) Find the linear speed of the sawteeth in ft/s. Incorrect: Your answer is incorrect. webMathematica generated answer key ft/
Answer:
The angular speed of the blade is of 166.67 rad/min
If a radial saw has a blade with a 9-in. radius. Suppose that the blade spins at 1000 rpm then the angular speed of the blade would be 104.72 rad/seconds.
What is speed?
The total distance covered by any object per unit of time is known as speed. It depends only on the magnitude of the moving object. The unit of speed is a meter/second. The generally considered unit for speed is a meter per second.
The mathematical expression for speed is given by
speed = total distance /Total time
As given in the problem If a radial saw has a blade with a 9-in. radius. Suppose that the blade spins at 1000 rpm then we have to find the angular speed of the blade,
the angular speed of the blade (ω) = 2πN/60
=2×π×1000/60
= 104.72 rad/seconds
Thus, the angular speed of the radial saw would be 104.72 rad/seconds
To learn more about speed from here,refer to the link;
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Calculate the average speed of blood flow in the major arteries of the body, which have a total cross-section area of about 2.0cm^2.
Answer:
0.9m/s
?
Explanation:
Someone please help and I will mark you as Brainlist! No
2) Translation kinetic energy is defined as the energy of a system due to the motion of the system’s...
• center of mass
• axis of symmetry
• molecules
• rotational movement
3) the work- energy theorem states that
• when work is done on a system, no energy changes can occur.
• when work is done on a system, a change in energy occurs.
• when energy is released by a system, work can be done.
• when work is done by a system, energy is released
Answer:
2) center mass
3) when work is done by a system, energy is released
Explanation:
State five uses of bases.
Answer:
Sodium hydroxide is used in the manufacture of soap. It is used in petroleum refining; in making medicines, paper, pulp, etc. It is used in making rayon. Calcium hydroxide is also known as slaked lime. It is used to neutralize acid in water supplies; in the manufacture of bleaching powder; as a dressing material for acid burns; as an antidote for food poisoning.Ammonium hydroxide is used to remove ink spots from clothes and to remove grease from window-panes. It is used in the cosmetic industry. Alkalis are used in alkaline batteries. Generally, potassium hydroxide is used in such batteries.Strontium hydroxide(Sr(OH)2) is used in the food industry for the refining of beet sugar.When the electrons reach the collector, they flow towards the positivly charged grid. The resulting current is measured. Note that as the electrons accelerate from the cathode toward the grid, they collide with the mercury atoms. Assume that these collisions are completely elastic. How does the collected current vary if the ΔVgrid is slowly increased? View Available Hint(s) When the electrons reach the collector, they flow towards the positivly charged grid. The resulting current is measured. Note that as the electrons accelerate from the cathode toward the grid, they collide with the mercury atoms. Assume that these collisions are completely elastic. How does the collected current vary if the is slowly increased? The current increases. The current remains constant. The current decreases.
Answer:
the current INCREASES.
Explanation:
In this experiment, the electrons are generated by a filament with very low speed, when they are subjected to a difference and potential ΔV they acquire the necessary speed to reach the regulation and the current can be measured.
Some electrons collide elastically with the atoms of the mercury gas that is much heavier and are scattered in any direction, so they do not reach the grid, by increasing the voltage this scattered electrons can acquire the necessary speed in the direction of grid to reach it and therefore are also measured, increasing the current.
Therefore, as the power difference increases, the current INCREASES.
The best leaper in the animal kingdom is the puma, which can jump to a height of 3.7m when leaving the ground at an angle of 45 degrees. with what speed must the animal leave the ground to reach that height?
Answer:
v = 12 m/s
Long, boring, and convoluted explanation:
First, let's lay out our information.
- max height = 3.7 m
- 0 = 45°
- gravitational acceleration constant = 9.8 [tex]\frac{m}{s^2}[/tex]
Since the puma leaves the ground at a 45 ° angle, its motion will follow a curved path as seen in many projectile motion problems, where the object is being influenced solely by the force of gravity. And because the puma leaves the ground at an angle, its initial velocity is broken down into its horizontal and vertical components. We were also told, though indirectly, that the max height is 3.7m because the puma can reach up to that height. Gravity is always given to be 9.8 [tex]\frac{m}{s^2}[/tex]
Because we are dealing with maximum height and gravity, we have to use the vertical component of the velocity, vsin ( θ ) , and not the horizontal component, vcos ( θ ) .
Given its max height, the acceleration due to gravity, and the angle, we can now solve for the speed at which the puma leaves the ground using the following equation: vsin ( θ ) = [tex]\sqrt{2hg}[/tex]
Where vsin ( θ ) is the vertical component of the initial velocity and h and g are max height and gravitational acceleration constant respectively.
Plugin, rearrange and solve
v sin ( θ ) = [tex]\sqrt{2hg}[/tex]
v sin ( 45 ∘ ) = √ 2 × 3.7 × 9.8
v ( 0.71 ) = [tex]\sqrt{72.52}[/tex]
v ( 0.71 ) = 8.52
v = 8.52 /0.71
v = 12 m s
A ball is rolling away from you at a constant speed, hits a wall, and then suddenly stops moving. Imagine a position-versus-time graph showing the ball’s motion. Describe the line on the graph.
Answer:
It would show a "straight line".
Explanation:
Newton's First Law of Motion states that an object at rest will remain at rest and an object in motion will remain in motion (at a constant velocity) unless acted upon by an unbalanced force. Newton's first law of motion is also called the law of inertia.
If a car travels 300 kilometers in 3 hours, its average speed is 100 km/hr.
O True
O False
Answer:
True
Explanation:
300/3=100km/hr
hope it helps. Plz mark me as brainliest.
Answer:
True
hope it helps u
thanks
There is a current of 0.83 A through a light bulb in a 120.0v circuit. What is the
resistance of the light bulb?
Answer:
144.6ohms
Explanation:
v=IR
R =V/I=120/0.83
R=144.6
After landing on an unfamiliar planet, a space explorer constructs a simple pendulum of length 54.0 cm. The explorer finds that the pendulum completes 98.0 full swing cycles in a time of 135s.
Required:
What is the value of g on this planet?
Answer:
g = 11.2 m/s²
Explanation:
First, we will calculate the time period of the pendulum:
[tex]T = \frac{t}{n}[/tex]
where,
T = Time period = ?
t = time taken = 135 s
n = no. of swings in given time = 98
Therefore,
[tex]T = \frac{135\ s}{98}[/tex]
T = 1.38 s
Now, we utilize the second formula for the time period of the simple pendulum, given as follows:
[tex]T = 2\pi \sqrt{\frac{l}{g}}[/tex]
where,
l = length of pendulum = 54 cm = 0.54 m
g = acceleration due to gravity on the planet = ?
Therefore,
[tex](1.38\ s)^2 = 4\pi^2(\frac{0.54\ m}{g} )\\\\g = \frac{4\pi^2(0.54\ m)}{(1.38\ s)^2}[/tex]
g = 11.2 m/s²
why is it important to observe safety rules in food preservation?
pls help
Answer:
Yes it is important.
Explanation:
It is important because we should preserve our food with safety as we would take it in the next day so if we we will not take safety then many germs can enter in that food and if we eat that food we could get sick . If we keep the food uncovered so anything can happen like any insect can fall in the food and we didn't know it it or any germs can enter in the food that is very harmful for our body so so we should keep the food covered and well preserved.
How does a sound wave's amplitude affect the sound we hear? How does a sound
wave's frequency affect the sound we hear?
Answer:
cause we hear differently
Explanation:
Answer:
As the amplitude of the sound wave increases, the intensity of the sound increases. Sounds with higher intensities are perceived to be louder. Relative sound intensities are often given in units named decibels (dB)
A beaker is filled with water. A small plastic container contains a solid bar of aluminum, which has a mass of 40 g, and is placed on the water so that it floats. The water level reads 60 ml. Next, the bar of aluminum is taken out of the container and placed in the water so that it sinks to the bottom. By how much does the water level change?
Answer:
25.2 ml
Explanation:
When the aluminium block is inserted in the container, the overall amount of only the water in the beaker can equal V o.
The weight of the water expelled by the plastic container should be equal to the weight of the aluminium block, according to the buoyancy balance relation.
i.e.
[tex]\rho_w V_wg = m_{Al}g = \rho_{Al}V_{Al} g \\ \\ V_w = \dfrac{\rho_{Al}V_{AL}}{\rho_{w}}[/tex]
When the aluminium block is inserted into the plastic container, the initial volume of water = 60 ml
[tex]V_i = V_o + V_w[/tex]
[tex]V_i = V_o + \dfrac{\rho_{Al}V_{Al}}{\rho_{w}}---(1)[/tex]
When the aluminium block is placed outside the container, the volume of the water
[tex]V_f = V_o +V_{Al} ---(2)[/tex]
By subtracting equation (1) and (2)
[tex]V_i -V_f = V_o + \dfrac{\rho_{Al} V_{Al}}{\rho_w}- ( V_o + V_{Al}}) \\ \\ =\dfrac{\rho _{Al}V_{Al}}{\rho_w}-V_{Al} \\ \\ = V_{Al} \Big( \dfrac{\rho_{Al}}{\rho_{w}}-1 \Big)[/tex]
since;
[tex]m_{Al} = 40 g[/tex]
[tex]V _{Al} = \dfrac{40 \ g}{2.7 \ g/cm^3} \\ \\ V_{Al} = 14.815 \ cm^3[/tex]
Similarly;
[tex]\dfrac{\rho_{Al}}{\rho_{w}}= \dfrac{2.7 }{1.0}[/tex]
= 2.7
[tex]V_i -V_f =14.815\Big( 2.7-1 \Big) \\ \\ V_i -V_f = 25.1855 \ ml \\ \\ = \mathbf{25.2 \ ml}[/tex]