Answer:
R = 0.14 Ω
Explanation:
The resistance of a metal is given by the relation
R = [tex]\rho \frac{L}{A}[/tex]
where ρ the resistivity is 5.6 10-8 Ω m, they also give the length and the cross section (area)
Let's reduce the magnitudes to the SI system
L = 200cm (1m / 100cm) = 2.00m
A = 8.0 10⁻⁷ m²
let's calculate
R = 5.6 10⁻⁸ [tex]\frac{2.00}{8.0 \ 10^{-7} }[/tex]
R = 1.4 10⁻¹ Ω
R = 0.14 Ω
An isotope has a half-life of 25 days. If you start with 50 grams, how much of the substance
will remain after 50 days? *
25 grams
12.5 g
6.75 g
Answer:
12.5
Explanation:
If the half life is 25 days then in 50 days it will half twice
50/2=25
25/2=12.5
A substance has a boiling point of 220 degrees Celsius and a melting point of −120 degrees Celsius. What state will it be at room temperature?
The substance with a boiling point of 220°C and a melting point of -120°C will be liquid at room temperature. The room temperature ranges from 15-35°C.
What is state of matter?The state of matter is the behavior of atoms and molecules present in a substance at a particular condition. There are three states of matter which include:
a. Solids: These are relatively rigid with a definite volume and shape, the atoms and molecules are attached to each other and vibrate in place,
b. Liquids: These are fluid in nature with a definite volume but not a definite shape, atoms and molecules are attached to each other by chemical bonds, and have more energy than solids,
c. Gases: In this state molecules do not have a definite shape nor a definite volume, the molecules are unstable as they carry maximum energy.
Boiling point of a substance is the temperature at which the vapor pressure of the liquid becomes equal to the pressure of surrounding (atmospheric pressure) of the liquid and the liquid therefore changes into the vapor state.
The process by which a solid substance changes to a liquid substance is called melting. The melting point is the temperature at which melting of a solid into a liquid takes place. The melting point of a substance is the same as the freezing point.
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Why is it incorrect to say iron is heavier than wood?
Answer: It is correct to say iron is heavier than the wood.
Explanation:
It's because the density of iron is more than wood. What is this mean is iron the space between iron molecules in iron much less than as that of wood. So in iron there is more molecules than wood in same volume. More molecules means more mass, that's why iron is much heavier than wood for same volume.
Alberto is walking east at 10 m/s from his house to his grandma's house. It takes him 30s to walk 50 m/s more to his grandma's house. What is his acceleration? *
Answer:
Acceleration = 1.33m/s² East
Explanation:
Given the following data;
Initial velocity = 10m/s
Final velocity = 50m/s
Time = 30secs
To find the acceleration;
In physics, acceleration can be defined as the rate of change of the velocity of an object with respect to time.
This simply means that, acceleration is given by the subtraction of initial velocity from the final velocity all over time.
Hence, if we subtract the initial velocity from the final velocity and divide that by the time, we can calculate an object’s acceleration.
Mathematically, acceleration is given by the equation;
[tex]Acceleration (a) = \frac{final \; velocity - initial \; velocity}{time}[/tex]
[tex]a = \frac{v - u}{t}[/tex]
Where,
a is acceleration measured in [tex]ms^{-2}[/tex]
v and u is final and initial velocity respectively, measured in [tex]ms^{-1}[/tex]
t is time measured in seconds.
Substituting into the equation, we have;
[tex]a = \frac{50 - 10}{30}[/tex]
[tex]a = \frac{40}{30}[/tex]
Acceleration = 1.33m/s² East
An automobile with a mass of 1000 kg accelerates at a traffic light with a force of 4000 N. What is the automobile's acceleration?
Explanation:
Given
mass (m) = 1000 kg
Force (F) = 4000 N
Acceleration (a) = ?
We have the relation
F = m * a
or, 4000 = 1000 * a
or a = 4000 / 1000
a = 4 m/s²
The acceleration of the automobile is 4 m/s²
Hope it will help :)❤
Answer:
[tex]\boxed {\boxed {\sf 4 \ m/s^2}}[/tex]
Explanation:
According to Newton's Second Law of Motion, force is equal to the product of mass and acceleration.
[tex]F=m*a[/tex]
We know the mass is 1000 kilograms and the force is 4000 Newtons. Let's convert the units to simplify the question for later.
1 Newton is equal to 1 kilogram meter per square second. The force of 4000 N is equal to 4000 kg*m/s²[tex]m= 1000 \ kg \\F= 4000 \ kg*m/s^2[/tex]
Substitute the values into the formula.
[tex]4000 \ kg*m/s^2=1000 \ kg *a[/tex]
We want to find the acceleration, a. We must isolate the variable on one side of the equation.
1000 kg and a are being multiplied. The inverse operatio of multiplication is division. Divide both sides of the equation by 1000 kg.
[tex]\frac{4000 \ kg*m/s^2 }{1000 \ kg } =\frac{1000 \ kg*a}{1000 \ kg}[/tex]
The kilograms will cancel.
[tex]\frac{4000 \ m/s^2 }{1000 }=a[/tex]
[tex]4 \ m/s^2 =a[/tex]
The autombile's acceleration is 4 meters per square second.
Object 1 and Object 2 have both the same mass. If object 1 moves twice as fast as Object 2, compare their kinetic energy.
A.) Object 1 has 1/4 the kinetic energy of object 2
B.) Object 1 has 1/2 the kinetic energy of object 2
C.) Object 1 has 2x the Kinetic energy of Object 2
D.) Object 1 has 4x the kinetic energy of object 2
Answer:
D.) Object 1 has 4x the kinetic energy of object 2
Explanation:
Kinetic Energy
Is the type of energy an object has due to its state of motion. It is proportional to the square of the speed.
The formula for the kinetic energy is:
[tex]\displaystyle K=\frac{1}{2}mv^2[/tex]
Where:
m = mass of the object
v = speed at which the object moves
Now suppose we have two objects with the same mass m1=m2=m and object 1 moves twice as fast as object 2, that is:
[tex]v_1=2v_2[/tex]
Let's compute their kinetic energies:
[tex]\displaystyle K_1=\frac{1}{2}mv_1^2[/tex]
[tex]\displaystyle K_2=\frac{1}{2}mv_2^2[/tex]
Since v1=2v2, the first kinetic energy is:
[tex]\displaystyle K_1=\frac{1}{2}m(2v_2)^2[/tex]
[tex]\displaystyle K_1=4\frac{1}{2}m(v_2)^2[/tex]
Dividing both equations:
[tex]\displaystyle \frac{K_1}{K_2}=\frac{4\frac{1}{2}m(v_2)^2 }{\frac{1}{2}m(v_2)^2}[/tex]
Simplifying:
[tex]\displaystyle \frac{K_1}{K_2}=4[/tex]
Or, equivalently:
[tex]K_1=4K_2[/tex]
Answer:
D.) Object 1 has 4x the kinetic energy of object 2
A tennis ball of mass 0.060 kg travels horizontally at a speed of 25m/s. The ball hits a tennis
racket and rebounds horizontally at a speed of 40 m/s.
Before hitting the Racket, the ball is going towards the racket at 25 m/s.
After Hitting the Racket the ball of going away from the racket at 40 m/s.
The ball is in contact with the racket for 50 ms.
What force does the racket exert on the ball?
A 0.018N
B 0.078N
C 18N
D 78N
The force does the racket exert on the ball will be 18 N. Force is defined as the product of mass and acceleration. Its unit is Newton.
What is force?Force is defined as the push or pull applied to the body. Sometimes it is used to change the shape, size, and direction of the body.
The given data in the problem is;
The mass of tennis ball is, [tex]\rm m= 0.060 \ kg[/tex]
The speed of tennis ball is,[tex]\rm u = 25m/s[/tex]
The rebound's speed is,[tex]\rm v = 40 \ m/sec[/tex]
The time period of ball is in contact,[tex]\rm t=50 \ ms =50 \times 10^{-3} \ sec[/tex]
The force on the rocket is found as;
[tex]\rm F= m [\frac{v-u}{t}] \\\\\ \rm F= 0.060[ \frac{40-25}{50 \times 10^{-3}} ]\\\\\ F= 18 \ N[/tex]
Hence, the force does the racket exert on the ball will be 18 N.
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Describe the disadvantages and advantages of using this element for dating.
Answer:Each method of dating has constraints around its use and effectiveness. Not all methods are well-suited for each situation – and sometimes it is just not possible to use a particular dating method.
Examples of some of the constraints of using a dating method include:
the size of the sample
the type of sample
contamination of the sample
the type of associated geo-archaeological materials
the need to minimise destructive testing
the chronologies involved
Explanation:
If a person is a regular marijuana user, they may be ...
A. under-performing at school.
B. over-achieving at school.
C. average at school.
Answer:
A
Explanation:
marijuana affects the brain
In this case, they may be under-performing at school. Hence, option (A) is correct.
What are habits?Routines that are routinely carried out are referred to as habits. They can also be characterized as behaviors brought on by an internal or external stimulus (Robbins & Costa, 2017). Additionally, habits are the actions you take in specific situations.
Perhaps someone else always brushes their teeth before going to bed. Basically, anything that is repeated frequently enough to become automatic might be considered a habit. You don't really need to consider doing it any more. It simply occurs.
Some would argue that our behaviors are what causes life (or at the very least, success). The routine actions we take shape who we are and the outcomes we attain. Because of this, developing healthy habits and breaking negative ones is a vital life skill that has numerous advantages.
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There are 30 students in Ms. Andrews’ fourth grade class. There are 6 times as many students in the entire fourth grade as there are in Ms. Andrew’s class. Which equation can be used to determine the number of students, n, in the entire fourth grade? *
6 x n = 30
6 + 30 = n
30 x 6 = n
30 ÷ n = 6
Answer:
30×6=n
Explanation:
30 students in her class× 6 = number of students in the entire 4th grade.
What technologies are in place to reduce ozone
Strategies currently being implemented include:
Vapor recovery nozzles at the gasoline pumps to reduce refueling emissions;
Cleaner burning gasoline reformulated to reduce VOC, NOx and other pollutants;
Strict NOx emission limits for power plants and industrial combustion sources;
Enhanced vehicle inspection programs in states; and
Strict limitations on the solvent usage in factories.
hope this helps
Question 5 of 20 :
Select the best answer for the question.
5. What kind of motor controller can automatically open and close ci
is energized?
O A. Semiautomatic
B. Faceplate
C. Magnetic contactor
D. Drum
Mark for review (Will be highlighted on the review page)
An object if moving according to this trajectory r=(-1+2t+t2, 3.t). What is the velocity of the object? What equation is describing the movement of the object? Is the object accelerating? How do you know?
Explanation:
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Calculus 1 : How to find acceleration
Study concepts, example questions & explanations for Calculus 1
Example Questions
Calculus 1 Help » Spatial Calculus » Acceleration » How to find acceleration
Find Acceleration : Example Question #1
The position vector of an object moving in a plane is given by r(t)=3t4i + 6t2j. Find its acceleration when t=1.
Possible Answers:
3i + 2j
36i + 12j
3i + 6j
6i + 2j
36i - 12j
Correct answer: 36i + 12j
Explanation:
To find acceleration at time t, we have to differentiate the position vector twice.
Differentiating the first time gives the velocity:
v(t) = r'(t) = 12t3i + 12tj
Differentiating a second time gives the accelaration:
a(t) = r''(t) = 36t2i + 12j
Plug in t=1 to solve for the final answer:
a(1) = r''(1) = 36i + 12j
Please show all the steps and work. The answer is -3.9 m/s2
Given that,
Initial velocity of the airplane = 66 m/s
Distance = 560 m
Final velocity of the airplane = 0 (stops)
To find,
Acceleration of the airplane.
Solution,
Let us consider that a is the acceleration of the airplane. We can find it using third equation of motion as follows :
[tex]v^2-u^2=2as\\\\a=\dfrac{v^2-u^2}{2s}\\\\a=\dfrac{0^2-66^2}{2(560)}\\\\a=-3.9\ m/s^2[/tex]
Therefore, the acceleration of the airplane is [tex]-3.9\ m/s^2[/tex]
Betty ran 5 km in 20 min. what is her speed in minutes?
Thanks + BRAINLIST
Please need correct answer asappp
5. Graph A plots a race car's speed for 5 seconds. The car's
rate of acceleration is 6 m/s?. True or false
A 50.0 kg shell is fired from a cannon on Earth's surface to a maximum height of 400 m. It then falls to a height of 100 m. What is the loss of potential energy as it falls?
Answer:
150,000 Joules.
Explanation:
Given that a 50.0 kg shell is fired from a cannon on Earth's surface to a maximum height of 400 m. It then falls to a height of 100 m. What is the loss of potential energy as it falls?
From Potential energy formula,
P.D = mgh
Assuming g = 10m/s^2
P.D = 50 × 10 × 400
P.D = 200000 Joules
Then it fell on 100m
The potential energy will be
P.D = 50 × 10 × 100
P.D = 50000 Joules
The lost Potential energy will be:
Lost P.D = 200000 - 50000
Lost P.D = 150000 Joules
Therefore, the loss of potential energy as it falls will be 150,000 Joules.
Someone please help me
I have attached the question
Answer:
Hydrogen
Explanation:
The atomic number is the number of protons in the nucleus :)
which roots are better underwater , taprroots or fibrous?
Answer:
The absorption of water and minerals by taproot is more efficient with the taproot system. Fibrous root absorbs water more efficiently as it reaches deep into the soil. Taproots are capable of withstanding drought.
Some gas is trapped in a large syringe by a piston.The atmospheric pressure is 100kpa.The pressure gauge indicates that the gas pressurr is 200kpa above atmospheric pressure.The piston moves outwards and the volume of the gas doubles.The temperature remains constant.What is the new gas pressure?
Answer: The new gas pressure is 150 kPa.
Explanation :
Boyle's Law: This law states that pressure is inversely proportional to the volume of the gas at constant temperature and number of moles.
[tex]P\propto \frac{1}{V}[/tex] (At constant temperature and number of moles)
[tex]P_1V_1=P_2V_2[/tex]
where,
[tex]P_1[/tex] = initial pressure of gas = (100+200) kPa = 300 kPa
[tex]P_2[/tex] = final pressure of gas = ?
[tex]V_1[/tex] = initial volume of gas = v
[tex]V_2[/tex] = final volume of gas = 2v
[tex]300\times v=P_2\times 2v[/tex]
[tex]P_2=150kPa[/tex]
Therefore, the new gas pressure is 150 kPa.
Does Santa Maria have a globe effect
Answer:
I don't think so
Explanation:
Answer:
yes
Explanation:
8. What will be the extension of a spring of K = 10 N/m, if the load is 75g?
Answer:
The extension of the spring is 7.35 cm
Explanation:
Spring Force
When a spring is compressed or extended by a distance x, it exerts a force given by the Hooke's Law:
F=k.x
Where k is the constant of the spring.
A mass of m=75 gr is hung to the spring of constant k=10 N/m. The force applied to the spring is the weight of the mass:
W = mg
The mass must be converted to kg:
m = 75/1000 = 0.075 kg
W=0.075*9.8
W = 0.735 N
The extension of the spring can be computed by solving for x:
[tex]\displaystyle x=\frac{0.735}{10}[/tex]
x=0.0735 m
x = 7.35 cm
The extension of the spring is 7.35 cm
Which feature of this rock demonstrates that it is a clastic sedimentary rock?
visible crystal formations
variation of colored sediments
visible rock fragments
distribution of organic materials
Answer:
visible rock fragments
Explanation:
sedimentary rocks start as sediments carried in rivers and deposited in lakes and oceans then get buried so the sediments lose water and become cemented to form the rock.
Answer:
c
Explanation:
In science, does acceleration happen when an object is slowing down?
Answer:
According to our principle, when an object is slowing down, the acceleration is in the opposite direction as the velocity. Thus, this object has a negative acceleration. In Example D, the object is moving in the negative direction (i.e., has a negative velocity) and is speeding up.
Which of these circuit schematics has an ammeter?
Α. Α
B. B
C. C
D. D
Answer:
d is the correct answer for this question hope it helps
Explanation:
when you see a A in a circle the the ammeter
Answer:
D.
Explanation:
PLATO
A rolling ball with a mass of 1.01 kg crashes into a wall. The wall exerts a force of 2.40 Newtons and stops the ball. What was the magnitude of the acceleration of the ball at the time of the crash?
Answer:
Acceleration, a = 2.38m/s²
Explanation:
Given the following data;
Mass = 1.01 kg
Force = 2.4N
To find the acceleration;
Force is given by the multiplication of mass and acceleration.
Mathematically, Force is;
[tex] F = ma[/tex]
Where;
F represents force.m represents the mass of an object.a represents acceleration.Making acceleration (a) the subject, we have;
[tex]Acceleration, a = \frac{F}{m}[/tex]
Substituting into the equation, we have;
[tex]Acceleration, a = \frac{2.4}{1.01}[/tex]
Acceleration, a = 2.38m/s²
Therefore, the magnitude of the acceleration of the ball at the time of the crash is 2.38 meters per seconds square.
A smooth wooden block is placed on a smooth wooden tabletop. You find that you must exert a force of 22.0 N to keep this 7.00 kg block moving at a constant
velocity of 4.00 m/s. What is the gravitational force acting on the wooden block?
A.) 7.00 N
B.) 68.7 N
C.) 22.0 N
D.) 78.5 N
Answer:
B . 68.7 N
Explanation:
Given in the question that;
Force = 22 N
Mass = 7.0 kg
Velocity = 4.0 m/s
Gravitational force is the weight of wooden block , calculated as mass times acceleration due to gravity.
F= m* a
F= 7 * 9.81
F= 68.67 N
F= 68.7 N
Saeed moves 50 m east then 65 m south to reach the garden. What is the displacement of Saeed?
Answer:
82.01m
Explanation:
Using the formula:
R^2=A^2+B^2
R= √ A^2+B^2
Where R= displacement
A=50m
B=65m
R= √ 50^2+65^2
R= √ 2500+4225
R= √ 6725
R=82.01m
The amount of air resistance acting on an object depends on the objects
Answer:
Shape of the object
Explanation:
This depends on the shape of the object. For a spherical object, a unitless value of 0.47 is typical. The magnitude of the velocity squared. The faster you go, the greater the air resistance force
