Answer:
0.2
Explanation:
The given parameters are;
The acceleration of the train, a = 0.2·g
The mass of the person standing on the train = m
Let μ represent the coefficient of static friction, we have;
The force acting on the person, F = m × a = m × 0.2·g
The force of friction acting between the feet and the floor, [tex]F_f[/tex] = m·g·μ
For the person not to slide we have;
The force acting on the person = The force of friction acting between the feet and the floor
F = [tex]F_f[/tex]
∴ m × 0.2·g = m·g·μ
From which we get;
0.2 = μ
The coefficient of static friction that must exist between the feet and the floor if the person is not to slide, μ = 0.2.
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26. D. crushing the sugar cube and dissolving it in water.
27. A. atom
28. B. molecule
29. B. plum pudding model of Joseph John Thomson
30. B. He used cathode ray tubes which showed that all atoms contain tiny negatively charged subatomic particles or electrons.
31. D. protons and neutrons are relatively heavier than electrons.
What is the relationship between Avogadro's number and a mole?
A. There are 6.02 x 1023 items in a mole, which equals Avogadro's
number
B. A mole is a smaller amount than Avogadro's number.
C. Avogadro's number is used to count particles, and a mole is used
to measure mass.
D. A mole applies to any item, but Avogadro's number is limited to
atoms.
SUBM
Answer:
A. There are 6.02 x 1023 items in a mole, which equals Avogadro's
number
Explanation:
The mole of a substance is
Ehy Newton's law of gravitation also called universal law?
Answer:
Gravity is a natural phenomenon that causes all massive objects to attract each other. The magnitude or force of this interaction depends on the masses and distance of the bodies. This causes objects to fall toward Earth, for example, and keep satellites and celestial bodies in their orbits, such as the Earth's orbit around the Sun. Gravity also causes the tidal phenomenon.
In physics, gravity can be approximated by Isaac Newton's laws of gravity. Although the accuracy of the law is sufficient, for example, when calculating the orbits of spacecraft, gravity is best described by Albert Einstein’s general theory of relativity, in which it is considered the curvature of space-time.
A stationary body explodes into four identical fragments such that three of them fly off mutually perpendicular to each other, each with same KE, E 0 . The energy of explosion will be Aa
Answer:
6Eo
Explanation:
An airplane with a ground speed of 550 km/hr travels along a heading of 30 degrees n of w at that high altitude there is a powerful 210 km/hr wind
Answer:
Determine the direction that the pilot is aiming the plane.
Explanation:
How much energy does it take to boil water for pasta? For a one-pound box of pasta
you would need four quarts of water, which requires 15.8 kJ of energy for every degree Celsius (°C) of temperature increase. Your thermometer measures the starting
temperature as 48°F. Water boils at 212°F.
a. [1 pts] How many degrees Fahrenheit (°F) must you raise the temperature?
b. [2 pts] How many degrees Celsius (°C) must you raise the temperature?
c. [2 pts] How much energy is required to heat the four quarts of water from
48°F to 212°F (boiling)?
Answer:
a. 164°F
b. [tex]91.\overline 1 \ ^{\circ} C[/tex]
c. [tex]140.\overline 4[/tex] kJ
Explanation:
The starting temperature of the water, T₁ = 48F
The temperature at which the water boils, T₂ = 212°F
a. The difference between the initial and the boiling water temperature, ΔT = T₂ - T₁
Therefore;
ΔT = 212°F - 48°F = 164°F
The temperature by which he temperature must be raised, ΔT = 164°F
b. 48°F = ((48 - 32)×5/9)°C = (80/9)°C = [tex]8.\overline 8 \ ^{\circ} C[/tex]
212°F = ((212 - 32)×5/9)°C = 100°C
∴ ΔT = 100°C - [tex]8.\overline 8 \ ^{\circ} C[/tex] = [tex]9.\overline 1 \ ^{\circ} C[/tex]
c. The heat capacity of the water = The heat required to increase four quartz of water by 1 °C = 15.8 kJ
∴ The heat required to raise four quartz of water by [tex]9.\overline 1 \ ^{\circ} C[/tex], ΔQ = 15.8 kJ/°C × [tex]9.\overline 1 \ ^{\circ} C[/tex] = [tex]140.\overline 4[/tex] kJ.
The acceleration of the car with two washers added to the string would be
Answer:
[tex]a=0.33\ m/s^2[/tex]
Explanation:
For washer 2,
v₁ = 0.13 m/s
v₂ = 0.36 m/s
t₁ = 1.92
t₂ = 2.61
We need to find the acceleration of waster 2.
[tex]a=\dfrac{v_2-v_1}{t_2-t_1}\\\\a=\dfrac{0.36-0.13}{2.61-1.92}\\\\a=\dfrac{0.23}{0.69}\\\\a=0.33\ m/s^2[/tex]
So, the acceleration of washer 2 is [tex]0.33\ m/s^2[/tex].
Answer:
.33
Explanation:
A scientist wants to use a model to help present results of his detailed scientific investigation
The decrease in the intensity of light over distance, such as with increasing depth in water, is known as ______.
Answer:
Attenuation
Step By step Explanation:
The decrease in the intensity of light over distance, such as with increasing depth in water, is known as ______.
It is called attenuation.
The decraese in the amplitude of the signals is called attenuation.
What is meant by measurement? l
Answer:
The action of measuring the size, length, or amount of something, as established is called measurement.
Explanation:
“Measurement” is the act of determining a target's size, length, weight, capacity, or other aspect. ... To use measurement tools as necessary. It is also appropriate to say that measurement is done by a worker using a measurement system, and instrumentation is done by a technician.
show that pv=nrt has the same unit with energy
Answer:
It is proved.
Explanation:
PV = n R T
where, P is the pressure, V is the volume, n is the number of moles, R is the gas constant, T is the absolute temperature.
Unit of pressure is Pascal= Newton/square meter = [tex][ML^{-1}T^{-2}][/tex]
Unit of volume is cubic meter = [tex][L^{3}][/tex]
So, the unit of P V
[tex][ML^{-1}T^{-2}] \times [L^{3}]\\\\[ML^2T^{-2}}[/tex]
[tex][ML^{2}T^{-2}][/tex]
It is same as the unit of energy.
hence proved.
A car is stationary. It accelerates at 0.8 ms^2
for 10 s and then at 0.4 ms^2
for a further 10 s. Use
the equations of motion to deduce the car’s final displacement. You will have to split the journey
into two parts, since the acceleration changes after 10 s.
Answer:
the car’s final displacement is 60 m
Explanation:
Given;
initail velocity of the car, u = 0
acceleration of the car, a = 0.8 m/s²
time of motion, t = 10 s
The first displacement of the car:
[tex]x_1 = ut + \frac{1}{2} at^2\\\\x_1 = 0 + \frac{1}{2} (0.8)(10)^2\\\\x_1 = 40 \ m[/tex]
The second displacement of the car;
acceleration, a = 0.4 m/s², time of motion, t = 10 s
[tex]x_2 = ut + \frac{1}{2} at^2\\\\x_2 = 0 + \frac{1}{2} (0.4)(10)^2\\\\x_2 = 20 \ m[/tex]
The final displacement of the car;
x = x₁ + x₂
x = 40 m + 20 m
x = 60 m
Therefore, the car’s final displacement is 60 m
please help me with this question
Answer:
(4) A = 3 A, A₂ = 11 A
(5) 7 A
Explanation:
(4)
From the diagram,
A = 3+6+2
A = 11 A
V = A₂R
A₂ = V/R₂............ Equation 1
Given: V = 12 V, R₂ = 4 Ω
Substitute these values into equation 1
A₂ = 12/4
A₂ = 3 A
(5) Applying,
V = IR'
I = V/R'............ Equation 1
Where V = Voltage, I = cuurent, R' = total resistance.
But,
1/R' = (1/3)+(1/4)
1/R' = (3+4)/12
1/R' = 7/12
R' = 12/7 Ω
Given: V = 12 V
Substitute these values into equation 1
I = 12/(12/7)
I = 7 A
Therefore
A = 7 A
4. Which of the following statement describes the particle model.
A. The average kinetic energy of the particles changes easily
B. All matter is made up of large triangular particles
C. There are no spaces between the particles
D. The average kinetic energy of all the particles remains constant
E.Other:
one car accelerates at half the rate of another how much longer does it take the first car to travel a quarter mile
Answer:
t=1/4v1
Explanation:
Given data
Car one
Speed =v1
Time =t
Distance =1/4 mile
Given data
Car two
Speed =v1/2
Time =t
Distance =d
Speed =distance/time
v1=1/4/t
v1t=1/4
t=1/4*1/v1
t=1/4v1 seconds
A car going around a curve with a radius of 15m experiences a centripetal acceleration of 2.5 m/s2. How fast is the car going?
0.17m/a
38 m/s
6.1 m/s
6.0 m/s
Answer:
Explanation:
The formula for centripetal acceleration is
[tex]a_c=\frac{v^2}{r}[/tex] . Filling in:
[tex]2.5=\frac{v^2}{15}[/tex] and
[tex]v=\sqrt{2.5(15)}[/tex] so
v = 6.1 m/s
Un proton penetra perpendiculares en un campo magnetico de 5 teslas con una velocidad de 2.10 m/s calcula
Answer:
The magnetic force acting on the proton is 1.68 x 10^-18 N.
Explanation:
magnetic field, B = 5 T
speed , v = 2.1 m/s
charge q = 1.6 x 10^-19 C
Angle, A = 90 degree
The magnetic force on the charge particle is given by
[tex]F = q v B sin A\\\\F = 1.6\times 10^{-19}\times 2.1\times 5\times sin 90\\\\F = 1.68\times 10^{-18} N[/tex]
The chart shows the speed at which light travels through different media.
In which medium would light have the longest wavelength?
- Water
- Air
- Glass
- Diamond
Answer:
Air.
Explanation:
To know which option is correct, let us consider the relationship between velocity and the wavelength of a wave. This is illustrated below:
Velocity, wavelength and frequency are related by the following equation:
Velocity = wavelength × frequency
v = λf
From the equation above, we can see clearly that the velocity is directly proportional to the wavelength.
This means that an increase in the wavelength will lead to an increase in the velocity and also, a decrease in the wavelength will lead to a decrease in the velocity.
Now, considering the table given in the question above, we can see that the wave has a higher speed in air. This simply means that the wave will also have a higher wavelength in air.
Thus, the correct answer to the question is: air
Mary drives at a speed of 35 mph (mile/hour). How long does it take for her to drive 98 miles?
__ hours
Answer:
2.8 hours
Explanation:
98 ÷ 35 = 2.8
Which part of this model represents a layer made of liquid rock that produces
a magnetic field?
A. B
B. A
C. D
D. C
Answer: C- the outer core
Explanation: The outer core is a thick layer of molten rock that encircles the inner core.
The U.S. has plans to build a 30-meter telescope, while the Europeans are thinking about a 39-meter telescope. What technological innovation allows astronomers to be thinking about telescopes with that large an aperture
Answer:
The mirror in these telescopes will be constructed from many smaller mirrors which will work together.
Explanation:
A telescope is defined as an optical instrument that is used to observe or view the distant objects. A telescope is made up of curved lenses or mirrors or by combining both.
In the context, both the US and the Europeans are planning to make a telescope which is 30 m and 39 m respectively. This could be possible as the mirrors that are used to make these telescope will be made from a many smaller mirrors that will work together as a single large mirror having a very large aperture.
State any ten reasons why students in Uganda need to study physics.(use examples of the possible technological advancements which can be made using the knowledge of physics)
Answer:
The answer is "physics ".
Explanation:
Physics is the branch of science that addresses the properties of crystalline and its interaction with the fundamental elements of the universe. It covers subjects ranging in quantum mechanics with extremely little ones with quantum mechanics to the whole cosmos. You must be constant whether you like it or not, thus everyone must learn physics, irrespective of whether they're in Uganda, and plenty of other countries should have physics to dare study.
The power of the kettle was 1.5 kW. The 0.2kg heating element took 5 seconds to heat from 20 °C to 100 °C. Calculate the specific heat capacity of water using this information.
Answer:
Specific heat capacity, c = 468.75 J/Kg°C
Explanation:
Given the following data;
Power = 1.5 kW to Watts = 1.5 * 1000 = 1500 Watts
Time = 5 seconds
Mass = 0.2 kg
Initial temperature = 20°C
Final temperature = 100°C
To find specific heat capacity;
First of all, we would have to determine the energy consumption of the kettle;
Energy = power * time
Energy = 1500 * 5
Energy = 7500 Joules
Next, we would calculate the specific heat capacity of water.
Heat capacity is given by the formula;
[tex] Q = mcdt[/tex]
Where;
Q represents the heat capacity or quantity of heat. m represents the mass of an object. c represents the specific heat capacity of water. dt represents the change in temperature.dt = T2 - T1
dt = 100 - 20
dt = 80°C
Making c the subject of formula, we have;
[tex] c = \frac {Q}{mdt} [/tex]
Substituting into the equation, we have;
[tex] c = \frac {7500}{0.2*80} [/tex]
[tex] c = \frac {7500}{16} [/tex]
Specific heat capacity, c = 468.75 J/Kg°C
is acting on an object that is constrained to move along the x-axis. If the force moves the object 3m, from the origin, what is the potential energy difference due to this force acting on the object
Answer:
U = - ∫ F dx
U = - 3F₀
Explanation:
Force and potential energy are related
F = [tex]- \frac{dU}{dx}[/tex]
dU = - F dx
∫ dU = - ∫ F dx
U- U₀ = - ∫ F dx
to solve the problem we must know the form of the force, if we assume that F = F₀ and U₀ = 0 for x = 0
U = - F₀ 3
Determine the amount of potential energy of a 4.2 kg book that is placed on a shelf with a height of 0.9 meters. Round your answer to one decimal place
Answer:
that is a correct answer maybe .
A 0.15-mm-wide slit is illuminated by light of wavelength 462 nm. Consider a point P on a viewing screen on which the diffraction pattern of the slit is viewed; the point is at 26.9° from the central axis of the slit. What is the phase difference between the Huygens' wavelets arriving at P from the top and midpoint of the slit?
Answer:
[tex]\triangle \phi=461.5rad[/tex]
Explanation:
From the question we are told that:
Silt width [tex]w=0.15=>0.1510^{-3}[/tex]
Wavelength [tex]\lambda=462nm=462*10^{-9}[/tex]
Angle [tex]\theta=26.9[/tex]
Generally the equation for Phase difference is mathematically given by
[tex]\triangle \phi=\frac{2 \pi}{\lambda}(\frac{wsin\theta }{2})[/tex]
[tex]\triangle \phi=\frac{2 \pi}{462*10^{-9}}(\frac{0.1510^{-3}*sin 26.9 }{2})[/tex]
[tex]\triangle \phi=461.5rad[/tex]
[tex]\triangle \phi=146.89\pi[/tex]
A student attaches a rope to a box and pulls the box up a ramp as shown below. The ramp has a rough surface. When
drawing the free body diagram for the box, the friction force should be directed:
O up and to the right
down and to the left
up and to the left
to the left
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What is potential energy? What are some of its examples.
Answer:
the energy stored in an object because of its specific state or position is called its potential energyexamples:-a compressed springWater that is behind a dam.A car that is parked at the top of a hill. a moving car.Etc....
Explanation:
❣️jess bragoli❣️#keep learning!!
Explanation:
POTENTIAL energy is the energy that is stored in an object due to its position relative to some zero position.
A shell is fired at an initial speed of 2500 m/s at an initial angle of 45 degrees. Find the shell's horizontal range and the amount of time the shell is in motion. (note that because it is fired from the ground to the ground, they displacement = 0.)
Answer:
d= 637323 meters
t= 360.5 seconds
Answer:
Explanation:
Since the height from which the shell was fired is the same as the height at which it lands (on the ground, to be specific), we will use the range equation. That is the only time you CAN use the range equation (when the initial height and the final height are exactly the same). The range equation is:
[tex]r=\frac{v_0^2sin(2\theta)}{g}[/tex] where v0 is the initial velocity, theta is the angle, and g is the pull of gravity (NOT negative). Filling in:
[tex]r=\frac{(1500)^2sin(9.0*10^1)}{9.8}[/tex] so, doing all that math gives us:
r = 6.4 × 10⁵ meters
When applying an arm sling, the injured arm's hand should be placed in a ________ position in the sling, and above the level of the elbow.
Answer:
The answer is "thumb-up".
Explanation:
The sling often called the arm sling, is a solution for preventing either shoulder or elbow motion during healing. A triangle bandage could be constructed.
A sling is a strong tissue loop that descends from the head to hold the forearm. The armrests in the sling bent also at the elbow.
The injured hand of the forearm should be positioned inside the pin position in the joint above the level of the elbow when putting the forearm sling.
