Answer:
42secs
Explanation:
v=u-gt
0=7-10t
10t=7
t=7/10
t=7/10*60
t=42
The amount of work done to bring an electron (q = −e) from right side of hydrogen nucleus to left side in the k shell is__________. Let the radius (r) of atom is 52 pm a) Zero b) infinity c) Fr d) 2Fr
Answer:
d) 2Fr
Explanation:
We know that the work done in moving the charge from the right side to the left side in the k shell is W = ∫Fdr from r = +r to -r. F = force of attraction between nucleus and electron on k shell. F = qq'/4πε₀r² where q =charge on electron in k shell -e and q' = charge on nucleus = +e. So, F = -e × +e/4πε₀r² = -e²/4πε₀r².
We now evaluate the integral from r = +r to -r
W = ∫Fdr
= ∫(-e²/4πε₀r²)dr
= -∫e²dr/4πε₀r²
= -e²/4πε₀∫dr/r²
= -e²/4πε₀ × -[1/r] from r = +r to -r
W = e²/4πε₀[1/-r - 1/+r] = e²/4πε₀[-2/r} = -2e²/4πε₀r.
Since F = -e²/4πε₀r², Fr = = -e²/4πε₀r² × r = = -e²/4πε₀r and 2Fr = -2e²/4πε₀r.
So W = -2e²/4πε₀r = 2Fr.
So, the amount of work done to bring an electron (q = −e) from right side of hydrogen nucleus to left side in the k shell is W = 2Fr
Suppose an object has a velocity of -7 m/s at t=0. What will the velocity be after 4 seconds if the acceleration of the object is +1 m/s^2?
Answer:
Vf = - 3 [m/s]
Explanation:
To solve this problem we must use the following equation of kinematics.
[tex]v_{f} =v_{o} +a*t[/tex]
where:
Vf = final velocity [m/s]
Vo = initial velocity = - 7 [m/s]
a = acceleration = 1 [m/s²]
t = time = 4[s]
Now replacing:
Vf = -7 + (1*4)
Vf = - 3 [m/s]
As the ball rolls down the ramp, there are changes in kinetic and potential energy. How much kinetic energy does the
ball have when it reaches point B?
A) 0J
B) 25J
C) 50J
D)100J
The answer is C, 50J
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Which experimental discovery led Niels Bohr to revise Rutherford's model of
the atom?
A. Most alpha particles pass straight through a thin sheet of gold
foil.
B. Electrons have more energy the farther they are from the nucleus.
C. A few alpha particles bounce off a thin sheet of gold foil.
D. The beam in a cathode ray tube is moved by an electric force.
Answer:
Electrons have more energy the farther they are from the nucleus.
Explanation:
A P E X
The total sum of atoms in an object.
Answer:
Mass
Explanation:
The total sum of atoms in an object is the mass of the object. There are several ways to quantify the number of atoms in a substance.
In chemical calculations, the number of moles is a good representation of the number of atoms contained in a body. Mass is the amount of substances a body has. If we can sum up all the atoms in a substance, one will arrive at the mass of the substance6. A total of 135 J of work is done on a gaseous refrigerant as it undergoes compression. If
the internal energy of the gas increases by 114 J during the process, what is the total amount
of energy transferred as heat? Has energy been added to or removed from the refrigerant as
heat?
Answer:
Eh = 21 [J]
Removed as heat.
Explanation:
This is a case of energy conservation, we have to take into account the energies that go in and out of the system. In this case, 135 [J] of energy are entered in the form of work of the compressor to the chamber where the refrigerant is compressed, now of these 135 [J] 114 [J] were used as internal energy, this internal energy is used to increase the pressure and temperature of the refrigerant.
In this way the rest of the energy of the 135 [J] was lost in the form of heat to determine this loss of energy, we simply perform the arithmetic subtraction.
Eh = 135 - 114 = 21 [J]
Eh = 21 [J]
The red car drive on a motor way in 800 m/s.The
driver of the Green car want to dive in that speed in
20 seconds.How many distance can he travel?
the value of g is greater at the poles than at the equator why
Answer:
because the gravitational pull is maximum at the poles and decreases as it comes down toward the equator.
What effect will the following have on the inertia of a body if
(i) the force acting on it is increased.
(ii) the mass of the body is reduced.
Explanation:
Inertia is the tendency of a body to remain at rest or to do nothing.
It is the resistance to any change in position of body.
When the force on a body increases, the inertia reduces
When the mass is reduced the inertia reduces
According to newton's first law or the law of inertia "an object will remain in its state of rest or of uniform motion unless if it is acted upon by an external force".
A car's acceleration is 3m/s2. If the car started at rest and it only took 10s for the car to reach this acceleration, what is the car's final velocity?
Answer:
30m/s
Explanation:
From law of motion equation
Vf= Vi + at
Where Vf= final velocity
Vi= initial velocity=0(the car started at rest)
a= acceleration= 3m/s2
t= time= 10s
Then substitute into the equation to get the final velocity.
Vf= 0+(10×3)
Vf= 30m/s
Hence, the car's final velocity is 30m/s
what do you know about healthy relationship true or false
Answer:
this question doesn't make sense
Explanation:
What is the Law of Conservation of Energy?
Answer:
The law of conservation of energy states that energy can neither be created nor destroyed - only converted from one form of energy to another.
Explanation:
Hope this helped, Have a Great Day!!
Line BD is the perpendicular bisector of CA. What additional information would be sufficient to prove that triangle BDA is congruent to triangle BDC by SAS.
Answer:
DA ≅ DC (since BD is equidistant to A and C)
Explanation:
A line bisector is one that divides a given line into two equal parts. And which is equidistant from the ends of the bisected line.
Given: BD is the perpendicular bisector of CA.
Thus:
BD is equidistant to A and C
Also, BD is a common side to ΔBDA and ΔBDC
DA ≅ DC (since BD is equidistant to A and C)
<BDA ≅ <BDC (congruent property)
<ADB ≅ <DBC (alternate angle property)
<CDB ≅ <ABD (alternate angle property)
Thus,
ΔBDA ≅ ΔBDC (Side-Angle-Side, SAS, congruent property)
A rope attaches a tire to an overhanging tree limb. A girl swinging on the tire has a
centripetal acceleration of 4.0 m/s2. If the length of the rope is 3.1 m, what is the girl's
tangential speed?
- A type of elevator called a cage is used to raise and lower miners in a mine
shaft. Suppose the cage carries a group of miners down the shaft. If the
unbalanced force on the cage is 60.0 N, and the mass of the loaded cage is
1.50 10 kg, what is the acceleration of the cage?
3. When a person is outside of the system and they add energy to the
system, we show this energy as
Answer:
We show added energy to a system as +Q or -W
Explanation:
The first law of thermodynamics states that, in an isolated system, energy can neither be created nor be destroyed;
Energy is added to the internal energy of a system as either work energy or heat energy as follows;
ΔU = Q - W
Therefore, when energy is added as heat energy to a system, we show the energy as positive Q (+Q), when energy is added to the system in the form of work, we show the energy as minus W (-W).
unit of power is derived unit why
Answer:
it was given the name Newton (N). from this, the derived unit of energy (or work) is defined ,as the work produced when the unit of force causes a displacement equal to the unit of length of its point of application along its direction . It was given the name Joule (J).
Explanation:
All elements are composed of extremely small particles called
After our sun leaves the main sequence it will most likely
A.) become a supergiant and explode in a supernova explosion
B.) become a giant and eventually form a black hole
C.) become a supergiant and eventually form a dwarf star
D.) become a giant and eventually form a dwarf star
Differentiate between the focus and the epicenter of an earthquake.
A bicycle travels 22 km in 0.50 hr. What is its average speed?
Answer:
22/0.50=44
Explanation:
average speed= distance / time
Cellular respiration takes place in the mitochondria of cells.
Answer:
True
Because mitochondria is the powerhouse of the cell.
Explanation:
Hope this helps you
Answer:
True
Explanation:
Which is the best description of a balanced diet?[food pyramid]
A. A vegetarian diet that includes no meat
B. A diet that consists of fewer than 2,000 calories per day
C. A diet that includes a wide variety of nutritious foods
D. A diet in which you eat at most three times a day
Answer:
A vegetarian diet that includes no meet is the best description of a balanced diet
Answer:
I should be B
Explanation:
extra characters lolhrhhdhfhdjdbfjsjf
The relationship that exists between gravity and distance and mass respectively.
A. The gravitational force is directly proportional to the distance between objects and inversely
proportional to the mass of the objects.
B. The gravitational force is inversely proportional to the distance between objects and directly
proportional to the mass of the objects.
C. The gravitational force is inversely proportional to the distance between objects and inversely
proportional to the mass of the objects.
D. The gravitational force is directly proportional to the distance between objects and directly
proportional to the mass of the objects.
Answer:
D...............................
What is the force required to move a 5,000 kg car with an acceleration of 4 m/s?
Answer:
20000
Explanation:
f=m*a
mass=5000
a=4
5000*4=20000
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the graph represents the motion of a car moving along a staright highway describe in words the motion car
A projectile has an initial x-velocity of 4 m/s, and an initial y-velocity of 27.7 m/s. What is the range of the projectile
Answer:
I love yourself help yourself
While john is traveling along a straight in interstate highway, he notices that the mile marker reads 242 mm. John travels until he reaches the 147 km marker and then retraces his path to the 161km marker. What is John's resultant displacement from the 242km marker? How far has he traveled answer in units of km
Complete Question
While john is traveling along a straight in interstate highway, he notices that the mile marker reads 242 km. John travels until he reaches the 147 km marker and then retraces his path to the 161 km marker. What is John's resultant displacement from the 242 km marker? How far has he traveled answer in units of km
Answer:
The resultant displacement [tex]\Delta x _{1 , 3} = 81 \ km[/tex]
The total distance traveled by john is [tex]x_t =109 \ km[/tex]
Explanation:
From the question we are told that
The first position of john from the finish point is [tex]x_1 = 242 \ km[/tex]
The second position of john from the finish point is [tex]x_2 = 147 \ km[/tex]
The third position of john from the finish point is [tex]x_3 = 161 \ km[/tex]
Generally the displacement from the 242 km marker is mathematically represented as
[tex]\Delta x _{1 , 3} = x_1 - x_3[/tex]
Here we used [tex]x_3[/tex] instead of [tex]x_2[/tex] because [tex]x_3[/tex] is further than [tex]x_2[/tex] from the finish point
=> [tex]\Delta x _{1 , 3} = 81 \ km[/tex]
Generally the total distance traveled by John is mathematically evaluated as
[tex]x_t = [x_1 - x_2 ] + [x_3 - x_2][/tex]
=> [tex]x_t = [242 - 147 ] + [161 - 147][/tex]
=> [tex]x_t =109 \ km[/tex]
with what force will the a car hit a tree if the car has a mass of 3,000 kg and a acceleration of 2m/s^2
Answer:
The answer is 6000 NExplanation:
The force acting on an object given it's mass and acceleration can be found by using the formula
force = mass × acceleration
From the question we have
force = 3000 × 2
We have the final answer as
6000 NHope this helps you
Is it possible to generate emf without rotating the coil explain
Answer:
It's not possible.
Explanation:
It's not possible.
This is because when a coil is rotated in a magnetic field about a line which is not the axis of the coil, the magnetic coil with a link going through the coil will change and thus an EMF will be produced.
Now, this EMF produced is gotten as a result of cutting action through lines of magnetic flux gotten through rotation (physical movement) of the coil through space.
Faraday's law allows finding the result for whether it is possible to create induced electromotive force (emf) without rotating the coil are:
Producing a pulsating voltage is possible change the magnetic field the area of the loop. Producing constant voltage is not possible since a uniform change of some parameter is required and the only one that can change is the angle constantly.
Faraday's Law states that by varying the magnetic flux an electromotive force is produced.
[tex]emf = - \frac{d \Phi_B }{dt} \\\Phi_B = B . A[/tex]
Where emf is the induced voltage, Ф the magnetic flux, B the magnetic field and A the area of the loop
We can write the flow explicitly.
Ф = B A cos θ.
Therefore we see that there is some form of having this changing flow:
Changing the magnitude of the magnetic field. Changing the area of the loop. Changing the angle between the normal to the area and the magnetic field direction.
The first two methods are used in pulsating fields, that is, a voltage is obtained for a short period of time.
The last method is used in equipment that can give indicated voltage in a constant way, it is the method used to produce electricity, it consists of an external system that rotates the loop with a constant speed and produces an output voltage.
In conclusion using Faraday's law we can find the result for whether it is possible to create induced electromotive force (emf) without rotating the coil are:
Producing a pulsating voltage is possible change the magnetic field the area of the loop Producing constant voltage is not possible since a uniform change of some parameter is required and the only one that can change is the angle constantly.
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