Answer:
The pressure exerted by the girl is 245,000 N/m²
Explanation:
Given;
mass of the girl, m = 50 kg
area of the girl's shoe, A = 0.002 m²
The pressure exerted by the girl is calculated as follows;
[tex]P = \frac{F}{A} \\\\Where;\\F \ is \ the \ force \ exerted \ by \ girl's \ weight\\\\P = \frac{F}{A} = \frac{mg}{A} = \frac{50 \times 9.8}{0.002} = 245,000 \ N/m^2[/tex]
Therefore, the pressure exerted by the girl is 245,000 N/m²
Which best describes the electric field created by a positive charge?
A. It circles clockwise around the charge.
B. It circles counterclockwise around the charge.
C. Its rays point away from the charge.
D. Its rays point toward the charge.
Answer:
Which best describes the electric field created by a positive charge? ... Its rays point toward the charge.
Explanation:
thank me later
A student is building an electric circuit.Which material should she choose for the wires,and why?
If i understand your question clearly, The best choice in most scenarios is copper.
Why?
Its due to copper's high conductive properties, its abundance, its low price compared to its fellow metal conductors, its ductile property, thermal resistance and immunity to oxidation ( rusting ).
Though Silver surpasses copper in conductivity, copper is shown to be more notable than its fellow conductors.
A pendulum is made by letting a 2.0-kg object swing at the end of a string that has a length of 2.1 m. The maximum angle the string makes with the vertical as the pendulum swings is 30°. What is the speed of the object at the lowest point in its trajectory?
Answer:
The speed of the object at the lowest point in its trajectory is:
[tex]v=2.34\: m/s[/tex]
Explanation:
We can use the conservation of energy between the maximum point of swing and the lowest point of the pendulum.
[tex]P=K[/tex]
[tex]mgh=\frac{1}{2}mv^{2}[/tex] (1)
Where:
h is the height of the object at 30° with the vertical.v is the speed at the lowest point.We can find h using trigonometry.
[tex]h=L-Lcos(30)=L(1-cos(30))[/tex]
[tex]h=2.1(1-cos(30))=0.28\: m[/tex]
Now, using equation (1) we can find v.
[tex]gh=\frac{1}{2}v^{2}[/tex]
[tex]2gh=v^{2}[/tex]
[tex]v=\sqrt{2gh}[/tex]
[tex]v=\sqrt{2(9.81)(0.28)}[/tex]
[tex]v=2.34\: m/s[/tex]
I hope it helps you!
Why does the output of a microphone increase as the frequency of the sound waves which it receives increases
Answer:
See Explanation
Explanation:
The frequency of sound waves received by the microphone influences the output or pitch of the sound obtained from the microphone.
The higher the frequency of the sound received by the microphone, the higher the output of the microphone and vice versa. This is because, the higher the frequency of sound, the higher the oscillations produced and the greater the output of the microphone.
The rise and fall in the pitch of sound waves as the frequency of sound waves varies is called inflection.
Answer:
b
Explanation:
cuz im smart
What are the three types of levers? Give examples of each?
Class 1 has the fulcrum placed between the effort and load. Class 2 has the load between the effort and the fulcrum. Class 3 has the effort between the load and the fulcrum.
...
Examples
Tweezers.
Stapler.
Mousetrap.
Broom.
Hockey stick.
definition of net force
Answer:
Net force is the vector sum of forces acting on a particle or body. The net force is a single force that replaces the effect of the original forces on the particle's motion. It gives the particle the same acceleration as all those actual forces together as described by Newton's second law of motion.
Explanation:
use this, but put it into you own words.
Answer:
The vector sum of forces acting on a particle or body is referred to as net force. The net force is a single force that replaces the effect of the original forces on the motion of the particle. It provides the particle with the same acceleration as all of the actual forces combined, as described by Newton's second law of motion.
°•°•°•°•°•°•°•°•°•°•°•°•°•°•°•°•
Hope it helps
Have a great day!!
A car has a kinetic energy of 103kJ.
The speed of the car is 13.1 m/s.
Calculate the mass of the car.
Give your answer to 2 significant figures.
Answer: 1200kg
Explanation:
KE = (1/2)mv^2
103kJ = 103000J
103000J = (1/2) * m * (13.1m/s)^2
Solve for m
A car has a kinetic energy of 103kJ, and the speed of the car is 13.1 m/s,then the mass of the car would have been 1200 kilograms.
What is mechanical energy?Mechanical energy is the combination of all the energy in motion represented by total kinetic energy and the total stored energy in the system which is represented by total potential energy.
A car has a kinetic energy of 103 kJ. The speed of the car is 13.1 m/s,
The kinetic energy of the car = 1/2 × mass × velocity
103000 =0.5 × mass × (13.1) ²
The mass of the car = 1200 Kilogram
Thus, if a car has a kinetic energy of 103kJ, and the speed of the car is 13.1 m/s,then the mass of the car would have been 1200 kilograms.
To learn more about mechanical energy, refer to the link;
https://brainly.com/question/2409175
#SPJ5
What's the meaning of longitudinal?
Answer:
A longitudinal study is a research design that involves repeated observations of the same variables over short or long periods of time. It is often a type of observational study, although they can also be structured as longitudinal randomized experiments.
Explanation:
The table describes the properties of four compounds.
Which compounds are most likely ionic?
compounds A and B
compounds B and C
compounds C and D
compounds D and A
Answer:
Last option
Explanation:
Marcel and Jose lifted 50 pounds as many times as they could. Marcel could lift the weight 25 times. Jose could lift the weight 30 times. Marcel and Jose can conclude that __________.
A.
Jose has better muscular endurance than Marcel
B.
Jose has better muscular strength than Marcel
C.
Marcel has better muscular strength than Jose
D.
Marcel has better muscular endurance than Jose
Answer:
A
Explanation:
Dùng một gương phẳng G để hắt 1 chùm ánh sáng mặt trời hẹp xuống đáy một cái giếng cạn hình trụ thẳng đứng dọc theo trục của giếng. Tính góc hợp bởi mặt gương và đường thẳng đứng, biết rằng các tia sáng mặt trời nghiêng với mặt phẳng nằm ngang một góc 60°C
Si se aplic una fuerza de 150N en un área de de 0.4m2¿cual será la preciosa ejercida?
Answer:
P = 375 Pa
Explanation:
The question says that,"If a force of 150N was applied in an area of 0.4m², what will be the precious exerted?"
We have,
Force, F = 150 N
Area, A = 0.4m²
We need to find the pressure exerted. We know that,
Pressure = forece/area
So,
[tex]P=\dfrac{150\ N}{0.4\ m^2}\\\\P=375\ Pa[/tex]
So, the required pressure is equal to 375 pa.
If the satellite weighs 1000g, orbits the Earth at an energy of 9.8 × 10 ^ 9j, what is the speed of the satellite?
Answer:
1.4×10⁵ m/s
Explanation:
Applying,
K = mv²/2............. Equation 1
Where K = Energy of the satellite, m = mass of the satellite, v = speed of the satellite.
make v the subject of the equation
v = √(2K/m)............ Equation 2
From the question,
Given: K = 9.8×10⁹ J, m = 1000 g = 1 kg
Substitute these values into equation 2
v = √(2×9.8×10⁹/1)
v = √(1.96×10¹⁰)
v = 1.4×10⁵ m/s
The length of an aluminium rod is 1m and the speed of sound along the rod is 5000 m per second .Find the values of f1 ad f2
Answer:
i. 2.5 kHz ii. 5 kHz
Explanation:
The frequency of the wave in the rod is given by f = nv/2L where n = harmonic, v = speed of sound in rod = 5000 m/s and L = length of rod = 1 m
i. f1
For f1, n = 1
f1 = 1 × v/2L
= v/2L
Substituting the values of the variables into the equation, we have
= 5000 m/s ÷ (2 × 1 m)
= 5000 m/s ÷ 2 m
= 2500 /s
= 2500 Hz
= 2.5 kHz
ii. f2
For f2, n = 2
f2 = 2 × v/2L
= v/L
Substituting the values of the variables into the equation, we have
= 5000 m/s ÷ 1 m
= 5000 /s
= 5000 Hz
= 5 kHz
A ball is kicked off of a roof at 23 m/s [R 25° U]. What is the height of
the building if it lands 2.8 s later?
Answer:
Explanation:
Considering the fact that we ave been given an angle of inclination here, we best use it! That means that the velocity of 23 m/s is actually NOT the velocity we need; I tell my students that it is a "blanket" velocity but is not accurate in either the x or the y dimension of parabolic motion. In order to find the actual velocity in the dimension in which we are working, which is the y-dimension, we use the formula:
[tex]v_{0y}=v_0sin\theta[/tex] and filling in:
[tex]v_{0y}=23sin(25)[/tex] which gives us an upwards velocity of 9.7 m/s. So here's what we have to work with in its entirety:
[tex]v_{0y}=9.7m/s[/tex]
a = -9.8 m/s/s
t = 2.8 seconds
Δx = ?? m
The one-dimensional motion equation that utilizes all of these variables is
Δx = [tex]v_0t+\frac{1}{2}at^2[/tex] and filling in:
Δx = [tex]9.7(2.8)+\frac{1}{2}(-9.8)(2.8)^2[/tex] I am going to do the math according to the correct rules of significant digits, so to the left of the + sign and to 2 sig fig, we have
Δx = 27 + [tex]\frac{1}{2}(-9.8)(2.8)^2[/tex] and then to the right of the + sign and to 2 significant digits we have
Δx = 27 - 38 so
Δx = -11 meters. Now, we all know that distance is not a negative value, but what this negative number tells us is that the ball fell 11 meters BELOW the point from which it was kicked, which is the same thing as being kicked from a building that is 11 meters high.
There are 8000 turns on the primary coil and 200 turns on the secondary coil of the transformer. The primary coil is connectd to a 240 v mains supply, suggest whether this transformer is a step up or step down transformer
Answer: Step down
Explanation:
Given
No of turns on the primary coil is [tex]N_p=8000[/tex]
No of turns on the secondary coil is [tex]N_s=200[/tex]
Primary is connected to the voltage [tex]V_p=240\ V[/tex]
According to the turns rule
[tex]\Rightarrow \dfrac{N_p}{N_s}=\dfrac{V_p}{V_s}\\\\\Rightarrow \dfrac{8000}{200}=\dfrac{240}{V_s}\\\\\Rightarrow V_s=\dfrac{240}{40}\\\\\Rightarrow V_s=6\ V[/tex]
As the voltage drops from 240 V to 6 V. Therefore it is a step-down transformer.
a 10 kg box is pulled across an ice rink for a distance of 50m. it is pulled with a constant force of 10 N on a rope angled at 60° to the horizontal. How much work is done on the box? (A) 50 ) (B) 100 ) (C) 250 ) (D) 500)
Answer:
(C) 250
Explanation:
Given the following data;
Mass = 10 kg
Distance = 50 m
Force applied = 10 N
Angle = 60°
To find the work done on the box, we would first of all find the horizontal component of the force applied.
[tex] Horizontal force, Fx = mgCosd[/tex]
Where;
Fx represents the horizontal force.
m is the mass of an object.
g is the acceleration due to gravity.
d is the angle of inclination (theta).
mg = weight = 10 N
Substituting into the equation, we have;
[tex] Fx = 10 * Cos60 [/tex]
[tex] Fx = 125 * 0.5 [/tex]
Fx = 5 Newton
Next, we find the work done.
Mathematically, workdone is given by the formula;
[tex] Workdone = force * distance[/tex]
Substituting into the formula, we have;
[tex] Workdone = 5 * 50 [/tex]
Workdone = 250 Nm
A hockey player uses a hockey stick to hit a puck such that the stick provides an applied force on the puck The puck travels for distance of 0.85 m while experiencing the force from the stick
The puck leaves the stick with a speed of 8.0 m/s and travels at constant speed in a straight line along the horizontalice for a distance of 12 m. The frictional force between the puck and the ice
surface is negligible
Which of the following statements best describes the force or forces exerted on the puck after it is hit by the stick and slides on the ice?
(A) The applied force from the stick is still exerted on the puck during this time.
Since the puck's acceleration is zero, there are no forces exerted on the puck during this time.
Since there is no frictional force exerted on the puck, a normal force is not exerted on the puck, but the gravitational force is exerted on the puck
There is no frictional force exerted on the puck and the gravitational force and normal force are exerted on the puck and are equal in magnitude
Answer:
Explanation:
Let's analyze the situation presented in order to know which answer is correct.
When the stick collides with the puck, it exerts a force for a certain time and discants. / After this time the horizontal force decreases to zero and the disk continues to move by the action of the initial velocity on the x axis and the acceleration of gravity on the y axis.
Therefore, after the collision, the only force that acts on the disk is the gravitational attractive force (WEIGHT), directed on the axis and in a negative direction.
The correct answer is:
C) Since there is no frictional force exerted on the puck, a normal force is not exerted on the puck, but the gravitational force is exerted on the puck
Earth's atmosphere _____. is made mostly of oxygen and carbon dioxide protects the surface from meteoroids and comets reflects most of the sun's heat and light back into space is very thin compared to the moon's atmosphere
Answer:
protects the surface from meteoroids and comets
Explanation:
Have a nice day
protects the surface from meteoroids and comets
two electrons (each with the charge of 1.6 x 10^ -19 c) are seperated by a distance of 5.4 x 10^ -5 c what is the electric force pushing them apart?
The electric force between two charges is:
F = (9 x 10⁹) Q₁ Q₂ / D²
F is the force, in Newtons
Q₁ and Q₂ are the two charges, in Coulombs
D is the distance between them, in meters
I'm going to assume that the first little 'c' in the question stands for "Coulombs", and the second little 'c' stands for "centimeters". And now, I'll proceed to answer the question that I've just invented.
For these two electrons:
F = (9 x 10⁹) (1.6 x 10⁻¹⁹) (1.6 x 10⁻¹⁹) / (5.4 x 10⁻⁷)²
F = (9 x 1.6 x 1.6 x 10⁻²⁹) / (5.4² x 10⁻¹⁴)
F = (23.04 / 29.16) x 10⁻¹⁵
F = 7.9 x 10⁻¹⁶ of a Newton
EACH electron feels that same force, pushing it away from the other electron.
uses of semiconductor
Answer:
Many digital consumer products in everyday life such as mobile phones / smartphones, digital cameras, televisions, washing machines, refrigerators and LED bulbs also use semiconductors.
A pendulum is moving 2.0 m/s at the bottom of its swing. How high vertically will it go before it begins to swing back? Group of answer choices 0.4 m 0.1 m 0.2 m 0.8 m 1.0 m
Answer:
h = 0.2 m
Explanation:
Given that,
A pendulum is moving 2.0 m/s at the bottom of its swing.
We need to find the height high it swing back. Let the height is h.
Using the conservation of energy such that,
[tex]\dfrac{1}{2}mv^2=mgh\\\\h=\dfrac{v^2}{2g}[/tex]
Put all the values,
[tex]h=\dfrac{(2)^2}{2\times 10}\\\\h=0.2\ m[/tex]
So, it will reach to a height of 0.2 m.
Can someone please help with part c)
Energy released ,
[tex] = 3.789 \times {10}^{ - 12} [/tex] J
Amelia is doing an experiment in which she is
going to burn various solid chemicals to see the
colors of flames they produce. For this laboratory
experiment, what types of safety precautions
should she take?
tie hair back
leave open flame unattended to get a drink
only burn the amount of chemicals as
directed by the lab procedure
put out the flame with water from the eyewash
station
Answer:
tie hair back
only burn the amount of chemicals as
directed by the lab procedure
Explanation:
The correct safety precautions for Amelia to take from the options would be to tie her hair back and to only burn the amount of chemicals recommended by the lab procedure.
With her hair left flowing freely, Amelia runs the risk of the hair catching flame while trying to burn the chemicals according to the procedure. Hence, tying her hair up into one neat bunch will limit the risk of it catching fire while working in the lab.
Also, burning less or more than the amount of chemicals recommended by the procedure may be dangerous or hinder Amelia from getting the right result.
Answer:
1,3
Explanation:
just did it
I am confused and need help with the question above??
a ball of mass 0.2 kg is dropped from a height of 20m on impact to the ground it loses in 30 joule of energy calculate the height it reaches on rebound
Answer:
5 m
Explanation:
We'll begin by calculating the original potential energy. This can be obtained as follow:
Mass (m) = 0.2 Kg
Height (h) = 20 m
Acceleration due to gravity (g) = 10 m/s²
Energy (E₀) =?
E₀ = mgh
E₀ = 0.2 × 10 × 20
E₀ = 40 J
Next, we shall determine the new energy of the ball.
Energy (E₀) = 40 J
Energy lost (Eₗ) = 30 J
New energy (E) =?
E = E₀ – Eₗ
E = 40 – 30
E = 10 J
Finally, we shall determine height of the ball on rebound. This can be obtained as follow:
New energy (E) = 10 J
Mass (m) = 0.2 Kg
Acceleration due to gravity (g) = 10 m/s²
Height (h) =?
E = mgh
10 = 0.2 × 10 × h
10 = 2 × h
Divide both side by 2
h= 10 / 2
h = 5 m
Thus, the height of the ball on rebound is 5 m
The diagram represents Earth in its orbit around the Sun and the Moon (M) in different positions in its orbit around Earth. Letters A through D represent four positions of Earth in its orbit. Earth is closest to the Sun near position D and farthest from the Sun near position B. Identify the lettered position of Earth and the Moon when this full moon phase can be observed, and state the name of the eclipse that could occur at this position.
Answer:
Option (D), lunar eclipse
Explanation:
When the moon comes between the earth and sun, the lunar eclipse occurs, so D is the lunar eclipse. It is full moon day.
C is the position when there is new moon day and it is solar eclipse.
So, option (D) is correct.
what is the name of part of the iss which provides it with electricity
pls help me solve this
Answer:
a) The uniform velocity travelled by the car is 10 meters per second.
(Point b has been erased by the user)
c) The distance travelled by the car with uniform velocity is 100 meters.
Explanation:
a) Calculate the uniform velocity travelled by the car:
The uniform velocity is the final velocity ([tex]v[/tex]), in meters per second, of the the uniform accelerated stage:
[tex]v = v_{o} + a\cdot t[/tex] (1)
Where:
[tex]v_{o}[/tex] - Initial velocity, in meters per second.
[tex]a[/tex] - Acceleration, in meters per square second.
[tex]t[/tex] - Time, in seconds.
If we know that [tex]v_{o} = 0\,\frac{m}{s}[/tex], [tex]a = 2\,\frac{m}{s^{2}}[/tex] and [tex]t = 5\,s[/tex], then the uniform velocity is:
[tex]v = 0\,\frac{m}{s} + \left(2\,\frac{m}{s^{2}} \right)\cdot (5\,s)[/tex]
[tex]v = 10\,\frac{m}{s}[/tex]
The uniform velocity travelled by the car is 10 meters per second.
(Point b has been erased by the user)
c) The distance travelled by the car ([tex]\Delta x[/tex]), in meters, with uniform velocity is calculated by the following kinematic expression:
[tex]\Delta x = v\cdot t[/tex] (2)
If we know that [tex]v = 10\,\frac{m}{s}[/tex] and [tex]t = 10\,s[/tex], then the distance travelled is:
[tex]\Delta x = \left(10\,\frac{m}{s} \right)\cdot (10\,s)[/tex]
[tex]\Delta x = 100\,m[/tex]
The distance travelled by the car with uniform velocity is 100 meters.
Alexis is a scientist who is studying solid-state physics. Which activity would she most likely do as a part of this research? O identifying the optimal vessel for containing carbon dioxide O studying the atomic structure of solid carbon dioxide O determining the effect of pressure on the volume of carbon dioxide O observing the natural state of carbon dioxide
Answer:
pretty sure its studying the atomic structure of a solid carbon dioxide. so c
Explanation:
Answer:
B. Studying the atomic structure of solid carbon dioxide
Explanation:
This is known as crystallography, the study of the arrangement of atoms in a solid, and it is a popular branch of solid-state physics.
Hope this helps :)