Answer:
b. 12.5 mAs, 70 kVp
Explanation:
The given parameter are;
The initial exposure factors := 10 mAs and 70 kVp
The initial Grid Ratio, G.R.₁ = 8:1
The Grid Ratio with which the radiographer desires to increase the scatter absorption, G.R.₂ = 12:1
Given that the lead content in the 12:1 grid, is higher than the lead content in 8:1 grid and that 12:1 grid needs more mAs to compensate, and provides a higher image contrast, the amount of extra mAs is given by the Grid Conversion Factors, GCF, as follows;
The GCF for G.R. 8:1 = 4
The GCF for G.R. 12:1 = 5
Therefore, given that the mAs used by the radiographer for 8:1 Grid Ratio is 10 mAs, the mAs required for a G.R. of 12:1 in order to maintain the same exposure is given as follows;
mAs for G.R. of 12:1 = 10 mAs × 5/4 = 12.5 mAs
Therefore the new exposure factors are;
12.5 mAs, 70 kVp
what happens to the force when the distance increases between 2 particales
(a) What is the escape speed on a spherical asteroid whose radius is 301 km and whose gravitational acceleration at the surface is 0.412 m/s2
Answer:
[tex]V.E=498.02m/s^2[/tex]
Explanation:
From the question we are told that:
Radius [tex]r=301Km[/tex]
Gravitational acceleration [tex]g=0.412 m/s^2[/tex]
Generally the equation for Escape velocity is mathematically given by
[tex]V.E^2=2gr[/tex]
[tex]V.E^2=2*0.412m/s^2*301000[/tex]
[tex]V.E^2=248024[/tex]
[tex]V.E=\sqrt{248024}[/tex]
[tex]V.E=498.02m/s^2[/tex]
As a girl pushes and object across a wood floor she suddenly comes to an area where the floor has been waxed recently making it slippery . What becomes true if the coefficient of kinetic friction
Answer:
This question is incomplete but the completed question is below
As a girl pushes an object across a wood floor, she suddenly comes to an area where the floor has been waxed recently, making it slippery. What becomes true of the coefficient of kinetic friction? A. The coefficient of kinetic friction increases. B. The coefficient of kinetic friction decreases. C. The coefficient of kinetic friction becomes zero. D. The coefficient of kinetic friction becomes negative.
The correct option is B
Explanation:
Coefficient of kinetic friction can be defined as the frictional force resisted by the motion of an object. From the question, it might take the girl to apply a force equivalent to just half that of the weight of the object to overcome friction to keep the object moving on a wood floor. Once she gets to the waxed area, the frictional force reduces, thereby also reducing the coefficient of kinetic friction further. Thus, she will be able to use less than half of the force (equivalent to less than half of the weight of the object) to push the object.
Thus, the correct option is B.
Can somebody help me understand this
Sí un auto viaja a 8m/s determine Tiempo en llegar a 200km de distancia Distancia que recorre en 40 minutos
Answer:
a. Tiempo = 25000 segundos
b. Distancia = 19200 metros
Explanation:
Dados los siguientes datos;
Velocidad = 8 m/s
Distancia = 200 km a metros = 200 * 1000 = 200,000
Para encontrar el tiempo para cubrir la distancia anterior;
Tiempo = distancia/velocidad
Tiempo = 200000/8
Tiempo = 25000 segundos
b. Para encontrar la distancia recorrida en 40 minutos;
Tiempo = 40 minutos a segundos = 40 * 60 = 2400 segundos
Distancia = velocidad * tiempo
Distancia = 8 * 2400
Distancia = 19200 metros
A dog wishes to swim across a slow moving stream. The current velocity is 3.0m/s. The distance directly across the stream is 50m. If the dog point himself directly across the stream, it will take .....
Answer:
Time = 16.667 seconds
Explanation:
Given the following data;
Distance = 50 meters
Velocity = 3 m/s
To find the time it will take;
Velocity can be defined as the rate of change in displacement (distance) with time. Velocity is a vector quantity and as such it has both magnitude and direction.
Mathematically, velocity is given by the equation;
Velocity = distance/time
Making time the subject of formula, we have;
Time = distance/velocity
Time = 50/3
Time = 16.667 seconds
Is torque only produced when the force is applied perpendicular to the moment arm?
The Torque is only produced when the force is applied perpendicular to the moment arm.
What is moment of force?The equal and opposite force acting at a point from the axis of rotation is called the moment.
M = F x r
Moment of force is also called as Torque.
Moment arm is the distance of the point of application of force from the axis of rotation of the body.
Thus, the perpendicular component only, produces the torque.
Learn more about moment of force.
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Assertion: When I P+ Q I = I P- QI, then P must be perpendicular to Q. Reason: The relation will hold even when Q is a null vector.
Answer:
The assertion is true and reason is false.
Explanation:
Assertion: I P+ Q I = I P- QI, then P must be perpendicular to Q.
Reason : The relation will hold even when Q is a null vector.
Now
[tex]\left | P + Q \right |=\left | P - Q \right |\\\\P^2 + Q^2 + 2 P Q cos \theta =P^2 + Q^2 - 2 P Q cos \theta\\\\4 P Q cos \theta = 0 \\\\cos \theta = 0 \\\\\theta = 90 degree[/tex]
So, P and Q are perpendicular to each other.
So, the assertion is true.
Reason is false.
a.in which portion of the curve,
1. is the velocity uniform.
2.is the velocity increasing.
3.is velocity decreasing.
4.is acceleration zero.
B. at which point does the body start to move and stop.
________________________
I will mark as brainlist
Answer:
the answer is 4 acceleration is 0
Explanation:
this is because when parallel line is drawn through x axis the velocity will bw uniform
plz brainliest
A system consists of multiple objects connected by ropes. How many equations need to be written to solve this problem?
A) two for each object
B) one or two for each object
C) one for each object
D) two for the system
Answer:
the correct answer is B
Explanation:
To solve the system they must have the same amount of unknowns as equations,
a) If the system does not have friction, we must write the x-axis equation for each body, therefore we need to write N equations
b) if the system has friction, two equations are needed for each particle
therefore the correct answer is B
help help help please please
Answer:
below
Explanation:
that is the procedure above
Gas to liquid with explanation on the basis of kinetic model and condensation point.
Answer:
Explanation:
1)Melting:
Melting is the process by which a substance changes from the solid phase to the liquid phase. ... Melting occurs when the internal energy of a solid increases, usually through the application of heat or pressure, such that the molecules become less ordered.
2) liquefication:
In physics and chemistry, the phase transitions from solid and gas to liquid (melting and condensation, respectively) may be referred to as liquefaction. The melting point (sometimes called liquefaction point) is the temperature and pressure at which a solid becomes a liquid.
3) vaporization:
Vaporization, conversion of a substance from the liquid or solid phase into the gaseous (vapour) phase. If conditions allow the formation of vapour bubbles within a liquid, the vaporization process is called boiling. Direct conversion from solid to vapour is called sublimation.
4) Sublimation occurs as molecules of a substance in the solid state go to the vapor state directly, rather than through the liquid state. ... ⭕In terms of the kinetic molecular theory, we know that molecules are in constant random motion, even when the substance is below the melting point.
In a cup game if the teams have the same score at the end of the match, 30 minutes of ------- are played.
Answer:
second lag
Explanation:
If in a cup game, a specified time limit is assigned to both teams to score high. If both teams are unable to score or if score of both the teams is equal then there is another second lag played where each team tries to score high. Even if in second lag both teams fail to score higher than other the last third lag is played or else game is declared draw.
What is the current flowing through the circuit shown? (V= 110 V, R, = 200, R2 = 300, R3 = 10 0) (Ohm's law: V = IR)
A. 1.8 A
B. 20 A
C. 0.05 A
D. 0.55 A
Answer:
A
Explanation:
The first thing you have to do is go back and list the resistances correctly. R1 = 20 R2 = 30 and R3 = 10.
Leave the units off if you can't make an omega.
The resistance of a series circuit (that's what this is) is r1 + r2 + r3 = 10 + 20 + 30 = 60 ohms
Now use ohms law.
R = 60 ohms
V = 110 volts.
I = V / R
I = 110/60
I = 1.833 to the nearest 1/10 = 1.8
A stone is thrown with an initial speed of 12 m/s at an angle of 30o above the horizontal from the top edge of a cliff. If it takes the stone 5.6 s to reach the bottom, how far does the stone travel horizontally
Answer:
[tex]d=58m[/tex]
Explanation:
From the question we are told that:
Initial Speed [tex]U=12m/s[/tex]
Time [tex]T=5.6s[/tex]
Angle [tex]\theta=30[/tex]
Generally the Newton's equation for motion is mathematically given by
[tex]d=d'+ut+\frac{at^2}{2}[/tex]
[tex]d=12cos30*5.6[/tex]
[tex]d=58m[/tex]
prove that vector addition obeys commutative and associative laws
the order of vector addition doesn't affect the resultant vector and grouping or order of pair doesn't effect the sum.
What is the correct equation for the y axis of object B?
Answer:
[tex]N_B-W_B = 0[/tex]
Explanation:
There are two forces acting on object B. If we consider the law of equilibrium, then the two forces must be equal in magnitude, for the object to remain in equilibrium position:
[tex]N_B = W_B\\\\N_B-W_B = 0[/tex]
Therefore, the correct answer of the given question, from the given choices, is:
[tex]N_B-W_B = 0[/tex]
Which two factors affect the size of the gravitational field?
Answer:
Explanation:
mass and distance
d. 'g' vanishes at centre of
6) A prism of 6° is made of material of refractive index What is the
deviation caused by it
d. 40
c.120
a. 60
b.8°
7) An object is placed 1cm from lens having magnification 5. Then its foc
length is
a. 0.8 cm b. 1.2 cm c. -1.2 cm d. -0.8cm
Answer:
a. 0.8 cm
Explanation:
The distance of the object from the lens, u = 1 cm
The magnification of the lens, m = 5
The focus of a lens formula is given as follows;
[tex]f = \dfrac{1}{\dfrac{1}{v} + \dfrac{1}{v} }[/tex]
The magnification of the lens, m = -v/u
Where;
v = The distance of the image from the lens
Therefore, we have;
v = m × u
∴ v = 5 × 1 cm = 5 cm (on the other side of the lens)
From which we get;
[tex]f = \dfrac{1}{\dfrac{1}{1} + \dfrac{1}{5} } = \dfrac{5}{6} \approx 0.8[/tex]
The focal length ≈ 0.8 cm
If mass is the amount of MATTER present in the
object, will it be different on Earth and the moon?
No
Yes
Answer:
Yes it would be different on Earth and the moon
Answer:
yes
Explanation:
The weight of a body is 600 N. What is the mass of the body on the surface of the earth?
Explanation:
soln,
weight=600N
mass=?
gravity=9.8 m/s²
now,
mass=weight/gravitymass=600/9.8mass=61.22kghope it helps.
stay safe healthy and happy.Answer:
m = 61.22 kg
Explanation:
F = 600 N
g = 9.8 m/s²
m = ?
F = mg
600 = m(9.8)
---> m = 61.22 kg
What is an electric fuse? What is the working principle of electric fuse?
If no braking occurs, a total of how much power would be required to keep the railcar moving at 40 m/s
Answer:
40 kW
Explanation:
A railcar has a continuous 1000 N decelerating force any time it is in motion. If no braking occurs, how much power would be required to keep the railcar moving at 40 m/s
Solution:
Power in Physics is the rate of doing work and the work can be mechanical, electrical, etc. The S.I unit of power is the watts (W).
The power required to keep the car moving must match the work done by the friction force (decelerating force) that tends to slow down the railcar.
Work done = Force * displacement
Power = Work done / time = (Force * displacement) / time
Power = Force * (displacement / time)
Power = force * velocity = 1000 N * 40 m/s = 40000 W
Power = 40 kW
¿Cuántos electrones por segundo pasan a través de una sección de alambre que lleva una corriente de 0.70 A.?
Answer:
The number of electrons flowing per second is [tex]4.375\times 10^{18}[/tex].
Explanation:
How many electrons per second pass through a section of wire that carries a current of 0.70 A.?
Current, I = 0.7 A
time, t = 1 s
According to the definition of current, let the charge is q.
q = I t
q = 0.7 x 1 = 0.7 C
Let the number of electrons is n.
[tex]n =\frac{q}{e}\\\\n = \frac{0.7}{1.6\times 10^{-19}}\\\\n = 4.375\times 10^{18}[/tex]
physics class 9 chapter 8 please tell please
Answer:
(a) The motion is uniform
(b) 11.11 m/s
Explanation:
(a)
From the table below, the motion of the bus is uniform.
(b)
Speed(s) = Δd/Δt
s = Δd/Δt............. Equation 1
From the table,
Given: Δd = 10 km = 10000 m, Δt = 15 minutes = (15×60) = 900 seconds
Substitute these values into equation 1
s = 10000/900
s = 11.11 m/s
Why would an airplane flying at 10,000 meters above the ground have more gravitational potential
energy than the same airplane flying at 1,000 meters above the ground?
Answer:
The gravitational potential energy (gpe) possessed by an object or body is directly proportional to the height of the object or body.
Explanation:
Gravitational potential energy (GPE) is an energy possessed by an object or body due to its position above the earth.
Mathematically, gravitational potential energy is given by the formula;
G.P.E = mgh
Where;
G.P.E represents potential energy measured in Joules.
m represents the mass of an object.
g represents acceleration due to gravity measured in meters per seconds square.
h represents the height measured in meters.
Generally, the gravitational potential energy (gpe) of an object or body is directly proportional to the height of the object or body. Thus, the gravitational potential energy of a body increases as the height of the body increases.
In conclusion, an object with a higher height would have a higher gravitational potential energy.
In 'coin on card' experiment a smooth card is used.
Answer:
In coin card experiment smooth card is used so that the card can slide easily from glass
What is the size of the force acting on a copper wire with a magnetic flux density of 3.6 x 10-2 T acting at
right angles to the wire of length 24 m and current of C:048 A? Give your answer to an appropriate
number of significant figures.
Answer:
F = 0.414 N
Explanation:
Given that,
Magnetic flux density,[tex]B=3.6\times 10^{-2}\ T[/tex]
The length of the wire, l = 24 m
Current, I = 0.48 A
We need to find the force acting on the wire. The formula for the force is given by:
[tex]F=ILB[/tex]
Put all the values,
[tex]F=0.48\times 24\times 3.6\times 10^{-2}\\\\F=0.414\ N[/tex]
So, the force acting on the copper wire is equal to 0.414 N.
The magnetic force of the copper wire is 41.472 N.
Magnetic force of the copper wire
The magnetic force of the copper wire is calculated by applying the following equation.
F = BIL x sinθ
Where;
θ is the inclination of the magnetic fieldI is the currentL is the length of the wireB is the magnetic field strength = flux densityF = (3.6 x 10⁻²) x (48) x 24 x sin(90)
F = 41.472 N
Thus, the magnetic force of the copper wire is 41.472 N.
Learn more about magnetic force here: https://brainly.com/question/13277365
Each tire on a car has a radius of 0.330 m and is rotating with an angular speed of 11.7 revolutions/s. Find the linear speed v of the car, assuming that the tires are not slipping against the ground. v
Answer:
The linear speed of the car, v, is 24.26 m/s
Explanation:
Given;
radius of the car's tire, r = 0.330 m
angular speed of the car, ω = 11.7 revolutions/s
The angular speed of the car in radian per second:
[tex]\omega = 11.7 \ \frac{rev}{s} \times \frac{2\pi \ rad}{1 \ rev} \\\\\omega = 73.523 \ rad/s[/tex]
The linear speed of the car, v, is calculated as;
v = ωr
v = 73.523 rad/s x 0.33 m
v = 24.26 m/s
Therefore, the linear speed of the car, v, is 24.26 m/s
A squirrel jumps into the air with a velocity of 4 m/s at an angel of 50 degrees. What is the maximum height reached by the squirrel?
Answer:
Explanation:
Assuming the squirrel is jumping off the ground, here's what we know but don't really know...
v₀ = 4.0 at 50.0°
So that's not really the velocity we are looking for. We are dealing with a max height problem, which is a y-dimension thing. Therefore, we need the squirrel's upward velocity, which is NOT 4.0 m/s. We find it in the following way:
[tex]v_{0y}=4.0sin(50.0)[/tex] which gives us that the upward velocity is
v₀ = 3.1 m/s
Moving on here's what we also know:
a = -9.8 m/s/s and
v = 0
Remember that at the very top of the parabolic path, the final velocity is 0. In order to find the max height of the squirrel, we need to know how long it took him to get there. We are using 2 of our 3 one-dimensional equations in this problem. To find time:
v = v₀ + at and filling in:
0 = 3.1 - 9.8t and
-3.1 = -9.8t so
t = .32 seconds.
Now that we know how long it took him to get to the max height, we use that in our next one-dimensional equation:
Δx = [tex]v_0t+\frac{1}{2}at^2[/tex] and filling in:
Δx = [tex]3.1(.32)+\frac{1}{2}(-9.8)(.32)^2[/tex] and using the rules for adding and subtracting sig fig's correctly, we can begin to simplify this:
Δx = .99 - .50 so
Δx = .49 meters
