Answer:
Explanation:
Im going to be using the rules for significant digits properly so I hope you're quite familiar with them. The equation we need for this is
F - f = ma where F is the applied force (our unknown), f is the frictional force, m is the mass, and a is the acceleration. Filling in:
F - 18.2 = 2.25(1.50) and
F = 2.25(1.50) + 18.2 Do the multiplication first and round to get
F = 3.38 + 18.2 The addition rules tell us that we will be rounding to the tenths place after we add to get
F = 21.6 N
An aluminum-alloy rod has a length of 10.0 cm at 20°C and a length of 10.015 cm at the boiling point of water (1000C). (a) What is the length of the rod at the freezing point of water (0 0C)? (b) What is the temperature if the length of the rod is 10.009 cm? /4mks
Answer:
a. 9.99625 cm b. 68 °C
Explanation:
(a) What is the length of the rod at the freezing point of water (0 0C)?
Before we find the length of the rod, we need to find the coefficient of linear expansion, α = (L - L₀)/[L₀(T - T₀)] where L₀ = length of rod at temperature T₀ = 10.0 cm, T₀ = 20 °C, L = length of rod at temperature T = 10.015 cm and T = 100 °C
Substituting the values of the variables into the equation, we have
α = (L - L₀)/[L₀(T - T₀)]
α = (10.015 cm - 10.0 cm)/[10.0 cm(100 °C - 20 °C)]
α = 0.015 cm/[10.0 cm × 80 °C]
α = 0.015 cm/[800.0 cm °C]
α = 0.00001875 /°C
We now find the length L₁ at T₁ = 0 °C from
L₁ = L₀(1 + α(T₁ - T₀))
So, substituting the values of the variables into the equation, we have
L₁ = L₀(1 + α(T₁ - T₀))
L₁ = 10.0 cm[1 + 0.00001875 /°C(0° C - 20 °C)]
L₁ = 10.0 cm[1 + 0.00001875 /°C × -20° C]
L₁ = 10.0 cm[1 - 0.000375]
L₁ = 10.0 cm[0.999625]
L₁ = 9.99625 cm
(b) What is the temperature if the length of the rod is 10.009 cm?
With length L₃ = 10.009 cm at temperature T₃, using
L₃ = L₀(1 + α(T₃ - T₀))
making T₃ subject of the formula, we have
L₃/L₀ = 1 + α(T₃ - T₀)
L₃/L₀ - 1 = α(T₃ - T₀)
T₃ - T₀ = (L₃/L₀ - 1)/α
T₃ = T₀ + (L₃/L₀ - 1)/α
substituting the values of the variables into the equation, we have
T₃ = 20 °C + (10.009 cm/10.0 cm - 1)/0.00001875 /°C
T₃ = 20 °C + (1.0009 - 1)/0.00001875 /°C
T₃ = 20 °C + 0.0009/0.00001875 /°C
T₃ = 20 °C + 48 °C
T₃ = 68 °C
True or false
scientific research has now proven that atoms are composed of parts that are larger than protons neutrons and electrons
Answer:
False
Explanation:
parts that are smaller than protons neutrons and electrons
A nucleus with mass number 229 emits a 3.443 MeV alpha particle. Calculate the disintegration energy Q for this process, taking the recoil energy of the residual nucleus into account.
Answer:
3.504 MeV
Explanation:
Given that;[tex]\frac{A}{Z} X ---->\frac{A-4}{Z-2} Y +\alpha + Q[/tex]
Also;
[tex]Q= KE_{\alpha } (M_{Y} + M_{\alpha } /M_{Y[/tex])
Mass number of X = 229
Mass number of Y = 225
Mass number of alpha particles = 4
Kinetic energy of alpha particles = 3.443 MeV
Q = 3.443 MeV (225 + 4/225)
Q= 3.504 MeV
Two rigid rods are oriented parallel to each other and to the ground. The rods carry the same current in the same direction. The length of each rod is 1.1 m, while the mass of each is 0.10 kg. One rod is held in place above the ground, and the other floats beneath it at a distance of 11 mm. Determine the current in the rods.
Answer:
220 A
Explanation:
The magnetic force on the floating rod due to the rod held close to the ground is F = BI₁L where B = magnetic field due to rod held close the ground = μ₀I₂/2πd where μ₀ = permeability of free space = 4π × 10⁻⁷ H/m, I₂ = current in rod close to ground and d = distance between both rods = 11 mm = 0.011 m. Also, I₁ = current in floating rod and L = length of rod = 1.1 m.
So, F = BI₁L
F = (μ₀I₂/2πd)I₁L
F = μ₀I₁I₂L/2πd
Given that the current in the rods are the same, I₁ = I₂ = I
So,
F = μ₀I²L/2πd
Now, the magnetic force on the floating rod equals its weight , W = mg where m = mass of rod = 0.10kg and g = acceleration due to gravity = 9.8 m/s²
So, F = W
μ₀I²L/2πd = mg
making I subject of the formula, we have
I² = 2πdmg/μ₀L
I = √(2πdmg/μ₀L)
substituting the values of the variables into the equation, we have
I = √(2π × 0.011 m × 0.1 kg × 9.8 m/s²/[4π × 10⁻⁷ H/m × 1.1 m])
I = √(0.01078 kgm²/s²/[2 × 10⁻⁷ H/m × 1.1 m])
I = √(0.01078 kgm²/s²/[2.2 × 10⁻⁷ H])
I = √(0.0049 × 10⁷kgm²/s²H)
I = √(0.049 × 10⁶kgm²/s²H)
I = 0.22 × 10³ A
I = 220 A
Which of the following changes occurs during nuclear fission?
A. Energy is absorbed from the surroundings.
B. Atomic nuclei combine to form a larger nucleus.
C. Energy is converted into mass.
D.
The parent nucleus splits into lighter daughter elements.
Reset
Answer:
The parent nucleus splits into lighter daughter elements
Explanation:
Nuclear fission involves the splitting of nucleus of a lighter element with smaller particles
Iron meteorites are interpreted as deriving from the cooled metallic core of a largeish asteroid. This is based upon:
Answer:
This is based upon the fact that meteorites are generally believed to have originated as solid debris from Larger bodies like meteoroid or asteroids
Explanation:
Iron meteorites are interpreted as deriving from the cooled metallic core of a larger asteroid , because meteorites are generally believed to have originated as solid debris from Larger bodies like meteoroid or asteroids that are located outside the planet but found their way into our planet .
Why does the needle of a compass point north?
a. Because the southern pole of the Earth's magnet repels it.
b. Because the southern pole of the Earth's magnet is in the north.
Because the northern pole of the Earth's magnet is in the north
d. Because the Earth's core is made of steel.
C.
Answer:
b. Because the southern pole of the Earth's magnet is in the north.
Explanation:
This is very weird to think about but Earth's southern magnetic pole is in Earth's geographic north. So when compass points north, it is actually getting attracted to the southern magnetic pole (that is actually located in the north direction- geographic location- in earth).
Which object will take the most force
to accelerate? *
4 kg
6 kg
8 kg
02 kg
Answer:
I think it might be 8kg grams because it is bigger
What are some core features of waves in physics?
Answer:
Waves are disorders that travel through a fluid medium. Several simple wave features include frequency, period, wavelength, and amplitude.
Explanation:
A beam strikes an irregular mirror and is reflected as shown below. The angle formed by the incoming beam and the reflected beam is 10 degrees. What is the angle of the mirror's surface (measured against vertical) at the location where the beam strikes the mirror?
A. The mirror's surface is angled 5 degrees upward where the laser strikes it.
B. The mirror's surface is angled 5 degrees downward where the laser strikes it.
C. The mirror's surface is angled 10 degrees upward where the laser strikes it.
D. The mirror's surface is angled 10 degrees downward where the laser strikes it.
Answer:
the correct answer is B
Explanation:
The law of reflection states that the angles of incidence and reflection on a surface are the same, the two rays and the normal are in the same part of the surface.
In this exercise indicate that the angle between the incident and reflected ray is 10, therefore the angle with respect to the normal that is a vertical line at the point of contact of the ray must be 5
Consequently the correct answer is B
Jorge tightens a bolt on his bicycle with a wrench that is 0.20 m long. If he pulls perpendicularly on the end of the wrench with a force of 140 N, how much torque does he apply ?
Answer:
28Nm
Explanation:
Torque is expressed as the prduct of force and radius
Given
Force = 140N
radius = 0.20m
Torque = 140 * 0.2
Torque = 140 * 1/5
Torque = 28Nm
Hence the amouunt of torque applied is 28Nm
In regard to the Compton scattering experiment with x-rays incident upon a carbon block, as the scattering angle becomes larger, what happens to the magnitude of difference between the incident and scattered wavelengths
Answer:
Increases
Explanation:
In the Compton scattering experiment with x-rays,
The change in operation
[tex]\Delta \lambda = \frac{h}{m_oc} [1-cos\theta][/tex]
Now rest being constant, as \theta increases, cos\theta decreases
Hence, The change in wavelength will increase with the increase in \theta.
Hence, wavelength increases with an increase in the angle of scatttering.
Which term BEST describes energy
stored in batteries and food?
potential energy
kinetic energy
heat energy
chemical energy
ik its a lot but can u help
Answer:
your correct ans is D.
object float in liquid when its density is less than liquid and sinks when its density is more than liquid..
stay safe healthy and happy.What are the si units
Answer:
The uniy which is accepted all over the world is called SI unit.
Explanation:
The system of measurement that is agreed by the international convention if scientists that is held in paris of France to adopt an international unit is called SI unit unit.
If a beaker with 300 ml of 20°C water is poured into a beaker with 400 ml of 30°C water, what is the final temperature?
Answer:
Explanation:
f the voltage in a circuit is 80 volts and the resistance is 20 ohms, what is the current?
I = 4 A
Explanation:
From Ohm's law, the voltage is given by
V = IR
or
I = V/R = (80 V)/(20 ohms)
= 4 A
8× +5+9×+3 how can I solve this
Answer:
collect like terms then add=>8x+9x+5+3
=>8x+9x+5+3=>17x+8
A parallel combination of 3ohms and 4ohms resistor is connected in series with a resistor of 4ohms and a battery of negligible resistance. Calculate the effective resistance in the circuit
Answer:
Explanation:
Equivalent resistance of parallel combination of two resistors of 3 ohms and 4 ohms .
R₁ = 3 x 4 / ( 3 + 4 )
= 12 / 7 = 1.7 ohms .
This equivalent resistance is connected with 4 ohms in series
Total resistance = 1.7 ohms + 4 ohms
= 5.7 ohms.
Hence effective resistance of the circuit = 5.7 ohms .
A positive charge is moving across a room from south to north. A magnetic field runs from east to west. In what direction is the magnetic force on the moving positive charge?
Answer:
the force is on the z axis, coming out of the blade
Explanation:
The direction of the magnetic force is given by the right hand rule,
For a positive charge, the thumb points in the direction of velocity, the other fingers extended in the direction of the magnetic field, and the palm points in the direction of force.
In this case.
Thumb points North
The fingers extended is in the east - west direction parallel to the blade
The palm is sticking out of the leaf, in the z direction
the answer is the force is on the z axis, coming out of the blade
Sound waves require a medium to travel. *
True
False
Answer:
false
Explanation:
Answer:
true
Explanation:
Space is not a medium. and we can not her anything in space. therefore you need a medium in order to hear sound waves.
La resistividad de cierto alambre es 1.72x10 -8 Ωm a 20 oC .Una batería de 6v se conecta a una bobina de 20 m de este alambre, con un diámetro de 0.8 mm. ¿Cuál es la corriente en el alambre?
Answer:
i = 1.09 10⁴ A
Explanation:
For this exercise we will look for the resistance of the wire
R = ρ L / a
the area of the wire is
a =ππ r² = π πd² / 4
we substitute
R = ρ L 4 / π d²
R = 1.72 10⁻⁸ 20 4/π 8 10⁻⁴
R = 5.47 10⁻⁴ Ω
to calculate the current we use ohm's law
V = R i
i = V / R
i = 6 / 5.47 10⁻⁴
i = 1.09 10⁴ A
You have just learned that the planet core of Mars is no longer radiating heat like the core of Earth. With this information what would you communicate to building designers as the lead geologist in regards to suitable building locations on the surface of Mars? Remember your informing builders about locations that would best avoid natural disasters like marsquakes and volcanoes? What evidence or theories do you have to support your statements?
Answer:
Explanation:
That is a fun question!
Without a hot radiating core like Earth, Mars will have very different geological and seismic events. The Mars core will be relatively cold and there will not be any molten magma. So Mars will not have earthquakes or volcano activities. Both only occur when there is magma flowing or tectonic plate motion and they will not occur with a cold core.
20 POINTS:
Why does the initial hill of a roller coaster need to be steep?
Answer: A roller coaster does not have an engine to generate energy. The climb up the first hill is accomplished by a lift or cable that pulls the train up. This builds up a supply of potential energy that will be used to go down the hill as the train is pulled by gravity
Hope this helps! Good luck with future homework and exams!
A (200 g) of water at (80 °C) is mixed with (100 g)of water at (20 °C). What is the final temperature of the water?
Answer:
60 °C
Explanation:
From the question given above, the following data were obtained:
Mass of 1st sample (M₁) = 200 g
Temperature of 1st sample (T₁) = 80 °C
Mass of 2nd sample (M₂) = 100 g
Temperature of 2nd sample (T₂) = 20 °C
Equilibrium temperature (Tₑ) =?
NOTE: Since the sample are the same, the specific heat capacity is constant.
We can obtain the equilibrium temperature as follow:
Heat lost by 1st = heat gained by the 2nd
M₁C(T₁ – Tₑ) = M₂C(Tₑ – T₂)
Cancel out C
M₁(T₁ – Tₑ) = M₂(Tₑ – T₂)
200 (80 – Tₑ) = 100 (Tₑ – 20)
Clear bracket
16000 – 200Tₑ = 100Tₑ – 2000
Collect like terms
16000 + 2000 = 100Tₑ + 200Tₑ
18000 = 300Tₑ
Divide both side by 300
Tₑ = 18000 / 300
Tₑ = 60 °C
Therefore, the equilibrium temperature (i.e the final temperature) of the mixture is 60 °C.
The length of a planet's day is determined by it's
Answer: "People will say the length of a day is determined by just the rotation rate of a planet, but that isn’t entirely true. The orbit around its sun also factors in. What we define as a day is the time between when the Sun is highest in the sky until the next time the Sun is at the highest point in the sky. This isn’t just the time it takes the Earth to rotate once on its axis, though. This is because, as the Earth is rotating, it’s also moving relative to the Sun"
ACELLUS PHYSICS HELP!!
A 6.93*10-4 C charge has a potential energy U = -3.09 J at a point in space. What is the electric potential V at that point? Include the sign, + or - . (Unit = V)
Answer:
Potential difference, V = -0.000224 Volts
Explanation:
Given the following data;
Quantity of charge = 6.93*10-4 C
Energy = -3.09 J
To find the electric potential V at that point?
Mathematically, the energy transferred per unit of charge is given by the formula;
E = QV
Where:
E is the energy
Q is the quantity of charge
V is the potential difference.
Substituting into the formula, we have;
[tex] -3.09 = 6.93*10^{-4} * V [/tex]
[tex] V = \frac {6.93*10^{-4}}{-3.09} [/tex]
Potential difference, V = -0.000224 Volts
If you were capable of converting mass to energy with 100%, efficiency, how much mass would you need to produce 3.5x10^12 Joules of energy?
Answer:
a) 3.9 x 10⁻⁵ kg
Explanation:
The amount of mass required to produce the energy can be given by Einstein's formula:
[tex]E = mc^2\\\\m = \frac{E}{c^2}[/tex]
where,
m = mass required = ?
E = Energy produced = 3.5 x 10¹² J
c = speed of light = 3 x 10⁸ m/s
Therefore,
[tex]m = \frac{3.5\ x\ 10^{12}\ J}{(3\ x\ 10^8\ m/s)^2} \\\\m = 3.9\ x\ 10^{-5}\ kg[/tex]
Hence, the correct option is:
a) 3.9 x 10⁻⁵ kg
A piston is resting halfway into a cylinder containing gas in thermal equilibrium. The layer of molecules next to the closed end of the cylinder is suddenly flash-heated to a very high temperature. Which best describes what happens next
Answer: hello the options related to your question is missing attached below are the missing options
answer : The molecules with the highest temperature will bounce off their neighbors, losing energy to them and so on until the system is at a new equilibrium with the piston moved out ( option B )
Explanation:
What best describes the situation of what will happen next as explained in the question is in Option B
Because molecules with higher temperatures will always posses higher kinetic energy and they will collide more frequently with surrounding molecules passing on their energy in the process until the energy gets to the molecules closest to the piston. The molecules closest to the piston will then hit the piston until a new equilibrium is achieved
Two people are sitting on wheeled chairs 1 metre apart. Person A is holding a 2kg ball. Person A throws the ball to Person. What happens to person A? Explain.
a.) their chair stays still
b.) chair rolls backwards
c.) chair rolls forwards
Answer:
B - Person A's chair rolls backwards.
Explanation:
This can be seen simply through the Conservation of Momentum. When the ball is thrown to be, the ball's momentum(+m) is transfererd to B, so B's chair moves forward(think about it - it makes sense, doesn't it?), meaning A's chair moves backwards.
So, B.
EXTRA TIP: Try drawing a diagram to help you!