Which is the best description of biodiversity?
1. All animals in an ecosystem
2. The variety of the type of life within the biosphere
3. The study of life
3. The variety of plants on Earth
Answer:2
Explanation:
How long must a 0.54-mm-diameter aluminum wire be to have a 0.42 A current when connected to the terminals of a 1.5 V flashlight battery
Answer:
L = 30.85 m
Explanation:
First, we calculate the resistance of the wire by using Ohm's Law:
V = IR
where,
V = Potential Difference = 1.5 V
I = Current = 0.42 A
R = Resistance of Wire = ?
Therefore,
[tex]R = \frac{1.5\ V}{0.42\ A}\\\\R = 3.57\ Ohms[/tex]
Now, the cross-sectional area of wire will be:
[tex]Area = A = \frac{\pi d^{2}}{4}\\\\A = \frac{\pi (0.00054\ m)^{2}}{4}\\\\A = 2.29\ x\ 10^{-7}\ m^{2}[/tex]
Now, the resistance of the wire is given as:
[tex]R = \frac{\rho L}{A}\\\\L = \frac{RA}{\rho}[/tex]
where,
L = Length of Wire = ?
ρ = resistivity of aluminum = 2.65×10⁻⁸ Ohm.m
Therefore,
[tex]L = \frac{(3.57\ Ohms)(2.29\ x\ 10^{-7}\ m^{2})}{2.65\ x\ 10^{-8}\ Ohm.m}[/tex]
L = 30.85 m
(a) What is the electric field 4.00 m from the center of the terminal of a Van de Graaff with a 3.00 mC charge, noting that the field is equivalent to that of a point charge at the center of the terminal?
______ N/C
(b) At this distance, what force does the field exert on a 2.00C charge on the Van de Graaff's belt?
_____ N
Answer:
a) E = 1.69 10⁶6 N / C, b) F = 3.38 10⁶ N
Explanation:
a) In this exercise using Gauss's law we can consider the charge of the generator sphere as if it were at its center, therefore the electric field is
E = k [tex]\frac{q}{r^2}[/tex]
let's calculate
E = 9 10⁹ 3.00 10⁻³ / 4²2
E = 1.6875 10⁶ N / C
E = 1.69 10⁶6 N / C
b) let's calculate the electric force
F = q E
F = 2.00 1.69 10⁶
F = 3.38 10⁶ N
10/12
11.
You drive the 10 miles to the mall at an average speed of 40 mph. On
the way home, you hit severe traffic and had to drive at an average
speed of 10 mph. What is your average speed for the trip?
How far can you get away from your little
brother with the squirt gun filled with
paint if you can travel at 3 m/s and you
have 15s before he sees you?
Know
Find
Equation
Solve
spray him in the eyes and you have until he washes it put
Help me please I wrote some but I am still stuck
Answer:
write something like after the spacecraft launched all of the potential energy transformed into kinetic energy causing the spacecraft to go at an abnormal spped.
Explanation:
A battery connected to two wires in parallel. Both wires are made of the same material and are of the same length, but the diameter of wire A is twice the diameter of wire B.
True or False for the following:
1) The resistance of wire B is four times as large as the resistance of wire A.
2) The power dissipated in wire A is 16 times the power dissipated in wire B.
3) The voltage drop across wire B is larger than the voltage drop across wire A.
4) The resistance of wire B is twice as large as the resistance of wire A.
5) The current through the battery is five times larger than the current through wire B.
Answer:
true 1
2 is false 2. 3 . 4. 5
Explanation:
For this exercise, let's calculate the different parameters and analyze the corresponding statements.
the resistance of each wire
R = ρ [tex]\frac{L}{A}[/tex]
wire B.
has a diameter of d₀
therefore its radius is r₀ = d₀ / 2
the area is A = pi r₀²
A = π d₀²/ 4
we subtitle
Ro = ρ [tex]\frac{L \ 4}{\pi d_o^2}[/tex]
R_b = R₀
wire A
the diameter is d = 2d₀
therefore the radius is r = d/2
r = d₀
resistance is
R_a = ρ [tex]\frac{L}{\pi d_o}[/tex]
R_a = 4 R₀
when examining the answers
1 is true
4 is false
Now let's calculate the power
P = V I
V = I R
P = V² / R
as they indicate that the cables are connected in parallel, the voltage in them is the same, therefore the potency depends on the resistance
wire B
P = V² / R_b
P_b = V² / R₀
wire A
P_a = v² / R_a
P_a = V² / 4R₀
P_a = ¼ P_b
2 is false
in a parallel circuit the waves are the same therefore
3 False
ohm's law is
V = I r
I = V / R
wire B
I_b = V / R_b
I_b = V / Ro
wire
I_a = V / R_a
I_a = V / 4 Ro
I_a = ¼ I_a
5 is false
.) What will be the unit of time in that system in
which unit of length is m, unit of mass is kg and
unit of force is kg wt?
(a) [1/V(9.8) second (b) (9.8)2 second
(c) V(9.8) second
(d) 9.8 second
Answer:
yes it is a great question. Thank you .
PLZ HELP IT URGENT
Describe what Rutherford would have seen in his gold foil experiment if J.J. Thompson's Plum Pudding model was completly accurate.
Answer: i use this in ss class
Explanation:
How long will it take a 200kg stationary man in space to travel 20m if he throws a 10 kg object at a velocity of 30m/s?
A polycondensation reaction takes place between 1.2 moles of a dicarboxylic acid, 0.4 moles of glycerol (a triol) and 0.6 moles of ethylene glycol (a diol). A.Calculate the critical extents of reaction for gelation using (i) the statistical theory of Flory and (ii) the Carothers theory.B.Comment on the observation that the measured value of the critical extent of reaction is 0.866.
Answer:
A) i) using statistical theory of floxy
(Pa)c = 0.816
(Pb)c = 0.816
ii) using Carothers theory
( Pc ) = 0.917
B) To Obtain the measured value of critical extent of reaction ( 0.866) 1 mol of Glycerol will react with 1 mol of dicarboxylic acid, but the same can not be applied to our obtained value because our stoichiometry is different
Explanation:
Given data :
Polycondensation reaction takes place between : 1.2 moles of dicarboxylic acid , 0.4 moles of glycerol and 0.6 moles of ethylene glycol
A) Calculate the critical extents of reaction for gelation
i) using statistical theory of floxy
(Pa)c = 0.816
(Pb)c = 0.816
ii) using Carothers theory
( Pc ) = 0.917
attached below is the detailed solution
B) To Obtain the measured value of critical extent of reaction ( 0.866) 1 mol of Glycerol will react with 1 mol of dicarboxylic acid, but the same can not be applied to our obtained value because our stoichiometry is different
HELP ASAP PLS ILL GIVE YOU BRAINLIEST
Select the correct answer.
Which civilization was the first to record a solar eclipse?
A.
Greek
B.
Chinese
C.
Aztec
D.
Polynesian
Answer:
chinese
Explanation:
Answer:
B chinese
hope this helps you
A monk is sitting atop a mountain in complete rest in meditation. What is the Kinetic
Energy of the monk? (assume mass of 65 kg and the mountain's height was 1000 m)
4,225,000
No Kinetic Energy - because there is no movement
637,000
65.000
Answer:
No kinetic energy-because there is no movement
Explanation:
It states that the monk is at complete rest so there is no movement.
Which one of the following is an example of an acid-base reaction?
Answer:
B
Explanation:
Acid reacts with base to give salt and water.
HCL - Acid
Mg(OH)2 - Base
H2O - Water
MgCl2 - Salt
Answer: B because A p e x
Explanation:
State the four factors the magnetic force moving in magnetic field depends on
Explanation:
It depends upon the magnitude of the charge, the velocity of the particle and its strength .
A spring with a spring constant of 80 N/m is at rest and is attached to a block. If the block (attached to the end of the spring) is moved from 0.6 m to 0.4 m and then let go, what will be the spring force exerted on the block? Rightward is positive.
Answer:
–I6 N
Explanation:
From the question given above, the following data were obtained:
Spring constant (K) = 80 N/m
Initial position = 0.6 m
Final position = 0.4 m
Force (F) =?
Next, we shall determine the compression of the spring. This can be obtained as follow:
Initial position = 0.6 m
Final position = 0.4 m
Compression (x) =?
Compression = Final position – Initial position
Compression (x) = 0.4 – 0.6
Compression (x) = – 0.2 m
Finally, we shall determine the force. This can be obtained as follow:
Spring constant (K) = 80 N/m
Compression (x) = – 0.2 m
Force (F) =?
F = Kx
F = 80 × –0.2
F = –I6 N
A 80 Kg monkey climbs a 15 meter tree in half a minute. What is the magnitude of power the monkey demonstrated?
a. 13.1 J/S
b. 392 J/S
c. 784 J/s
d. 11760 J/s
Answer:
Power = Work / Time
P = m g h / t = 80 kg * 9.8 m/s^2 * 15 m / 39 s = 320 N m/ s = 392 J / s
= 392 Watts
The magnitude of power the monkey demonstrated is equal to 392 J/S.
Power calculation
To measure the power of a given body, one must relate its weight, the displacement performed and the time in which the movement was performed, in such a way:
[tex]P = \frac{m\times g\times d}{t}[/tex]
Thus, applying the values given by the statement we have:
[tex]P = \frac{80 \times 9.8 \times 15}{30}[/tex]
[tex]P = 392 J/s[/tex]
So, the power performed by the monkey climbing 15 meters is equal to 392J/s.
Learn more about power in: brainly.com/question/8671146
g A particle is trapped in a 20 nm wide infinite potential well. What is the wavelength of the particle corresponding to n
Question:
A particle is trapped in a 20 nm wide infinite potential well. What is the wavelength of the particle corresponding to n = 7 in nm?
Answer:
[tex]\lambda_n = 5.71\ nm[/tex]
Explanation:
Given
[tex]L = 20nm[/tex] --- the width
[tex]n = 7[/tex]
Required
Determine the wavelength ([tex]\lambda[/tex])
This is calculated as:
[tex]\lambda_n = \frac{2L}{n}[/tex]
Substitute values for L and n
[tex]\lambda_n = \frac{2*20nm}{7}[/tex]
[tex]\lambda_n = \frac{40nm}{7}[/tex]
[tex]\lambda_n = \frac{40}{7}nm[/tex]
[tex]\lambda_n = 5.71428571\ nm[/tex]
[tex]\lambda_n = 5.71\ nm[/tex] --- approximated to 3 significant figures
liquids have higher coefficents of expansion than solids do in general. ture or false worth 29 points!
Answer:
true
Explanation:
Consider a length of pipe bent into a U-shape. The inside diameter of the pipe is 0.5 m. Air enters one leg of the pipe at a mean velocity of 100 m/s and exits the other leg at the same magnitude of velocity, but moving in the opposite direction. The pressure of the flow at the inlet and exit is the ambient pressure of the surroundings. Calculate the magnitude and direction of the force exerted on the pipe by the airflow. The air density is 1.23 kg/m3 .
Answer:
The magnitude of the force exerted on the pipe by the air is 4830 N and it acts horizontally
Explanation:
Given the data in the question;
from the Newton's second law of motion;
F = ma
where m is the mass, a is acceleration and F is the force exerted on the pipe due to the airflow in it
now in terns of mass flow;
F = [tex]m^{"}[/tex]V
where [tex]m^{"}[/tex] is the mass flow rate, V is the velocity(
so
[tex]m^{"}[/tex] = pAV
[tex]m^{"}[/tex] = p × ([tex]\frac{\pi }{4}[/tex] d² ) × V
where d is the diameter of the pipe( 0.5 m)
p is the density( 1.23 kg/m³ )
velocity v is 100 m/s
so we substitute
[tex]m^{"}[/tex] = 1.23 × ([tex]\frac{\pi }{4}[/tex] (0.5)² ) × 100
[tex]m^{"}[/tex] = 30.75 × [tex]\frac{\pi }{4}[/tex]
[tex]m^{"}[/tex] = 24.15 kg/s
Now lets write the equation for the force exerted on the pipe by the airflow
F = [tex]m^{"}[/tex]( V₁ - V₂)
where V₁ is velocity at inlet ( 100 m/s )
V₂ is velocity at exit ( - 100 m/s )
so we substitute
F = 24.15 ( 100 - (-100))
F = 24.15 × 200
F = 4830 N
The pipe is symmetric about horizontal axis so the force should also b acting only in the horizontal direction since any force component in the vertical direction is nullified due to this symmetry
Therefore, The magnitude of the force exerted on the pipe by the air is 4830 N and it acts horizontally
Find the moment of 300N force about B
Answer:
300
Explanation Hope I'm not wrong.
How is the chemical bonding within a molecule of carbon dioxide (CO2) different from the chemical bonding within a crystal of iron (Fe)?
A.
In an iron crystal, the atoms are joined by sharing electrons. In carbon dioxide, atoms of carbon and oxygen are held together by freely moving electrons.
B.
In a carbon dioxide molecule, atoms of carbon and oxygen are joined by sharing electrons. In an iron crystal, the atoms are held together by freely moving electrons.
C.
In an iron crystal, the atoms are joined by their opposite electrical charges. In carbon dioxide, atoms of carbon and oxygen are held together by freely moving electrons.
D.
In a carbon dioxide molecule, atoms of carbon and oxygen are joined by their opposite electrical charges. In an iron crystal, the atoms are held together by freely moving electrons.
Answer:
I'ts B
Explanation:
:p
The chemical bonding within a molecule of carbon dioxide (CO2) different from the chemical bonding within a crystal of iron (Fe) in a carbon dioxide molecule, atoms of carbon and oxygen are joined by sharing electrons. In an iron crystal, the atoms are held together by freely moving electrons. Therefore, option B is correct.
What is chemical bonding ?The term chemical bonding is defined as the formation of a chemical bond between two or more atoms, molecules, or ions to form a chemical compound.
There are three main types of chemical bonding that are ionic bonding, covalent bonding, and metallic bonding.
The chemical bonding within a molecule of carbon dioxide (CO2) different from the chemical bonding within a crystal of iron (Fe) because in a carbon dioxide molecule, atoms of carbon and oxygen are joined by sharing electrons. In an iron crystal, the atoms are held together by freely moving electrons.
Thus, option B is correct.
To learn more about the chemical bonding, follow the link;
https://brainly.com/question/12907148
#SPJ2
The manufacturer of a 9V dry-cell flashlight battery says that the battery will deliver 20 mA for 80 continuous hours. During that time the voltage will drop from 9 V to 6 V. Assume the drop in voltage is linear with time. How much energy does the battery deliver in this 80 h interval
Answer:
17280 J or 17.28 kJ
Explanation:
Given that the voltage drop,
U = U2 - U1
U = 9 - 6
U = 3V
Also, we're told that the current, I is equal to 20 mA with the discharge time, t being 80 hrs.
Converting the time from h oi urs to seconds, we have
t = 80 * 3600
t = 288000
Now, to find the energy needed, we're going to use the formula
w = pt, where p = U * I
p = 3 * 20*10^-3
p = 60*10^-3
w = 60*10^-3 * 288000
w = 17280 J or 17.28 kJ
Therefore, the total energy the battery delivers in the 80 hrs is 17.28 kJ
A high frequency sound will have a ?
Answer:
The frequency of a sound wave is what your ear understands as pitch. A higher frequency sound has a higher pitch and the lower the period
Answer:
High-frequency sound waves produce high-pitched sounds, and low-frequency sound waves produce low-pitched sounds.
Friction occurs when microscopic hills and valleys stick together
true or false
Answer:
true
Explanation:
Friction occurs because no surface is perfectly smooth. Rougher surfaces have more friction between them. Heavier objects also have more friction because they press together with greater force. Friction produces heat because it causes the molecules on rubbing surfaces to move faster and have more energy.
Explanation:
true but not going to copy and paste,
An uncharged capacitor and a resistor are connected in series with a switch and a 12 V battery. At the instant the switch is closed, the voltage across the resistor is
Answer:
V = 12 V
Explanation:
Since a capacitor can't change the voltage between its plates instantaneously, this means that just after the switch is closed, the voltage through the capacitor is zero.So, the current that flows in this moment is the same that would flow in a series circuit with only one resistor connected to the battery.Applying KVL to the circuit (neglecting the presence of the capacitor which can be replaced by a short circuit just after closing the switch), the voltage through the resistor must be equal to the one of the battery, i.e., 12 V.A 0.15kg baseball is pushed with a 100N force. What will its acceleration be?
How do intermolecular forces (IF) and internal kinetic energy (KE) compare in gases?
IF = 0, KE is large
IF < KE
IF ≥ KE
IF > KE
Please help me!
Answer:
IF < KE
Explanation:
The kinetic energy of the gas is greater than the intermolecular forces making the molecules have room to move around without disruption. In a lot of gases, there are sometimes no intermolecular forces between all the particles.
Best of Luck!
all of the following elements will form ions by losing electrons except
aluminum
iron
sodium
oxygen
Consider the following three concentric systems two thick shells and a solid sphere all conductors The radii in the increasing order are a b c d and e The small sphere is given an excess charge of 3 C and the smaller shell is given an excess charge of 7 C The larger shell is electrically neutral The system quickly comes to electrostatic equilibrium state a Note that there are 5 conducting surfaces What are the electric charges values and signs on the each of them Are these charges distributed uniformly
Answer:
Explanation:
From the given question, the small sphere was provided with an excess charge of +3 C, while the smaller shell was given an excess of -7 C, it should be -7 C and not 7 C.
So, in light of that, to determine the electric charges values & signs on each of them, we have:
on a = +3 C
on b = -7 C
on c = -7 C
on d = +3 C
on e = -7 C