Answer:
fr = 7.84 N
Explanation:
To solve this exercise we must use Newton's second law, the case of translational equilibrium
F -fr = 0
F = fr
where F is the applied force and fr the friction force
for the Y axis
N -W =
N = W
N = m g
the friction force has the equation
fr = μ N
fr = μ m g
in this case they indicate the two materials that are in contact with wood on wood, so when reviewing the tables the coefficient of static friction is μ=0.4
let's calculate
fr = 0.4 2.0 9.8
fr = 7.84 N
what allows electrons to move through it easily
Answer:
materials that allow many electrons to flow freely are caused conductors such as copper, silver, aluminum, hydrochloric solution, sulfuric acid, and salt water. in contrast materials which allow few electrons to flow are called insulators such as plastic, rubber, glass, and dried paper.
Explanation:
Hope this helped Mark BRAINLEST!!
True or False. The fulcrum of a first class lever is between the output force and an input force.
Answer:
True
Explanation:
A first-class lever is a lever in which the fulcrum is located between the input effort and the output load. In operation, a force is applied (by pulling or pushing) to a section of the bar, which causes the lever to swing about the fulcrum, overcoming the resistance force on the opposite side
If the sun were to burn out, it would take humans just over 8 minutes to realize because light from the sun takes just over 8
minutes to reach earth. Tommy was 3 years old when his dad showed him a particular star that was estimated to be 18 light years
away from earth. If the star burned out immediately after Tommy was showed it, how old would Tommy be before he realized the
star was gone?
A)
21 years old
B)
18 years old
9 years old
D)
6 years old
the answer is (a. 21
Answer:the answer it’s A) I just took the test on USATestPrep
Explanation:
what does it mean for a disease to be X linked?
Answer:
X-linked is a trait where a gene is located on the X chromosome. Humans and other mammals have two sex chromosomes, the X and the Y. In an X-linked or sex linked disease, it is usually males that are affected because they have a single copy of the X chromosome that carries the mutation.
4. A cinder block is sitting on a platform 20 m high. It has a mass of 4 kg. The block has energy. Calculate it.
784 J
3136 J
847
80 J
Answer:
Explanation:
Since the block is at rest in an elevated position, we can assume that it only has potential energy.
U=mgh is the formula for potential energy where U=potential energy, m= mass, g=acceleration due to gravity, and h=height.
Plug in known variables....
U=4kg*9.8m/s^2*20m
U=784 joules of potential energy or letter A.
What happens to the electrons when the atoms are close but not touching?
Answer:
If the atoms get two close then the nuclii will repell each other.
Explanation:
Since electrons are negative they are attracted to the nucleus because it is positive. If two atoms get close enough together then the electrons of each atom will be attracted to both nuclii.
what is fast carbon and what is slow carbon
please dont search it up need this right now extra points!
Answer:
the fast carbon cycle follows the movement of carbon through living (biotic) components of an ecosystem. This occurs faster because life moves more quickly. The fast carbon cycle focuses primarily on the biosphere, while the slow carbon cycle is more involved with the hydrosphere, lithosphere and atmosphere.
Explanation:
please help me i neeed help with all threeas soon as possible thank you
Answer:
4b: comets
5a: supercluster
5b: they just changed 4b's solar system for milky way. I think it is still comets. if not, then just say black holes.
who was the chairman of drafting committe
Antarctica's landscape is proof that ____.
A. a large amount of water does not make a continent habitable
B. it has the highest levels of precipitation in the world
C. humans cannot survive at extremely high altitudes
D. a continent covered in snow can be one of the driest on earth
Answer:
The answer to the equation is B hope this helps:)
Answer:
D. a continent covered in snow can be one of the driest on earth
Explanation:
How many degrees are there between the direction of motion and the force of friction?
A. O
B. 270
C. 90
D. 180
The correct option is (d).
Angle should be 180° between the direction of force and the direction of motion of a body as work done is equal to force multiplied by displacement multiplied by cosx.
Friction is a force that opposes motion. When two objects are in contact, friction is acts in a direction opposite to the motion of the object.A force known as friction prevents relative motion between surfaces that are in touch. One of the more basic features of friction is that it always runs parallel to the surfaces with which it makes contact and opposes any motion or attempted motion of the systems with respect to one another.What is the direction of friction force?When a force is applied to stop it from moving, frictional force provides resistance. As a result, it always moves in the opposite direction of an item in motion. Friction acts on the right when force is applied to the left.Learn more about direction of friction force brainly.com/question/24322020
#SPJ2
Could somebody pls help me out with this?
1) You serve a Volleyball with a mass of 1.6kg. the ball leaves your hand with a speed of 25m/s. the ball has________energy. Calculate it.
2) Askateboard is sitting at the top of a hill that is 26m high. the skateboard weighs 2 N. the skateboard has _____energy. Calculate it.
Rain and wind place which type of load on structures?
A) Dynamic load
B) Soft load
C) Gradual load
D) Static load
A skydiver falls out of a plane from rest, and experiences no air resistance. Eventually, this skydiver reaches a velocity of 33 m/s. How much time did this take? *
Answer:
the time taken for the motion is 3.37 s
Explanation:
Given;
initial velocity of the skydiver, u = 0
final velocity of the skydiver, v = 33 m/s
The time taken for the motion is calculated as;
v = u + gt
33 = 0 + 9.8t
33 = 9.8t
t = 33 / 9.8
t = 3.37 s
Therefore, the time taken for the motion is 3.37 s
1.Coral reefs are endangered by?
a. Climate change b. pollution C. overfishing d. all of the above
Answer:
I'm going to go out on a limb and say D. All of the above
Explanation:
The adult house fly lives for only about 1 month, or 8 x 10^-2 y. The oldest recorded age of a tortoise was 1.8800 x 10^2 y. What is the difference between these two ages?
187.92 years
8*10^-2= .08
1.88*10^2= 188
188-.08=187.92
A 0.225 kg sample of tin initially at 97.5°c is dropped into 0.115 kg of water. the initial temperature of the water is 10.0°c. if the specific heat capacity of tin is 230 j/kg • °c, what is the final equilibrium temperature of the tin-water mixture
Answer:
The final equilibrium temperature of the tin-water mixture is approximately 18.468 °C
Explanation:
The parameters of heat energy transfer from the tin to the water are given as follows;
The mass of the sample of tin, m₁ = 0.225 kg
The initial temperature of the tin, T₁ = 97.5 °C
The mass of the water into which the tin is dropped, m₂ = 0.115 kg
The initial temperature of the water, T₂ = 10.0 °C
The specific heat capacity of tin, c₁ = 230 J/(kg·°C)
The specific heat capacity of water, c₂ = 4,200 J/(kg·°C)
Let 'T' represent the final equilibrium temperature of the tin-water mixture, we have;
The heat lost by the tin, ΔQ[tex]_{tin}[/tex] = The heat gained by the water ΔQ[tex]_{water}[/tex]
∴ ΔQ[tex]_{tin}[/tex] = ΔQ[tex]_{water}[/tex]
Where;
ΔQ[tex]_{tin}[/tex] = m₁·c₁·(T₁ - T)
ΔQ[tex]_{water}[/tex] = m₂·c₂·(T - T₂)
By substitution, we have;
ΔQ[tex]_{tin}[/tex] = 0.225 kg × 230 J/(kg·°C) × (97.5°C - T)
ΔQ[tex]_{water}[/tex] = 0.115 kg × 4,200 J/(kg·°C) × (T - 10.0°C)
From ΔQ[tex]_{tin}[/tex] = ΔQ[tex]_{water}[/tex], we have;
0.225 kg × 230 J/(kg·°C) × (97.5°C - T) = 0.115 kg × 4,200 J/(kg·°C) × (T - 10.0°C)
∴ 5,045.625 J - 51.75 J/°C × T = 483 J/°C × T - 4,830 J
5,045.625 J + 4,830 J = 534.75 J/°C × T
∴ 534.75 J/°C × T = 9,875.625 J
T = 9,875.625 J/(534.75 J/°C) = 18.4677419 °C ≈ 18.468 °C
The final equilibrium temperature of the tin-water mixture, T ≈ 18.468 °C.
As an astronaut travel far away from earth her weight
Explanation:
As an astronaut travel far away from the earth her weight Decreases because weight depends upon the acceleration due to gravity and in space there is no gravity.
Anybody knows this thanks !
Answer:
225J
Explanation:
1/2mvsq=1/2×50×9
Answer:
b. 225 J
Explanation:
Velocity (v) = 3 m/s
Mass (m) = 50 kg
[tex]K. E. = \frac{1}{2} m {v}^{2} \\ \\ = \frac{1}{2} \times 50 \times {3}^{2} \\ \\ = 25 \times 9 \\ \\ = 225 \: j [/tex]
Which of the following statements is false?
Dissolving salt into water is an example of a mixture.
The mass of one piece of paper is the same even after it is ripped in half and the 2 pieces are measured again.
Increasing the temperature of water to a boil is a physical change.
The formation of a precipitate is the only way to see if a chemical change has occurred.
which of the following correctly describes the hierarchy of genetic material within a cell
Answer: D- Each chromosome in a cell is made up of two chromatids, which are each made up of molecules of DNA
Explanation:
A macromolecule is a large molecule that is made of many smaller units. Chromosomes are macromolecules that contain all of the genetic information in a cell. Chromosomes are each made of two smaller units called chromatids. Chromatids are each made up of molecules of DNA. Therefore, the correct description of the hierarchy of genetic material in a cell is that each chromosome in a cell is made up of two chromatids, which are each made up of molecules of DNA. The structures become more and more microscopic as one moves down the hierarchy.
1. How do we tell how much energy a ray of light has?
By it's temperature
By it's color
By it's brightness
2. Which of the following are common forms of energy released by electrons dropping from heightened energy levels?
Light, Heat
Motion, Sound
Light, Kinetic
Heat, Potential
4. Describe the shape of a field created by a bar magnet.
5. On a microscopic scale, the energy change in a system is described by a
A change in color or texture
Measuring the temperature
A chemical equation
An odor
6. The aurora borealis lights that appear in the northern hemisphere are caused by the interaction between what?
Ultraviolet radiation from the Sun and the pollution in the Earth's air
The reflected light off the moon and the scattering particles in the atmosphere
The charged particles from the Sun and natural magnetic field of the Earth
7. What happens to the atoms of a material when you run electricity through that material?
The bonds that hold the atoms together begin to stretch due to the electric current
The neutrons, having no charge, resist the flow the electric energy through the atom
The electricity only goes into atoms that have an overall electric charge of the same orientation of the electric flow
8. The amount of potential energy stored in a magnetic field depends on what?
The size of one magnetic pole
How close two magnet poles are to each other
The number of molecules magnetically aligned in a pole
Whether the pole is a North or South pole magnet
9. Compare and contrast microscopic and macroscopic energy transfer. Give at least three comparisons for each.
10. A plane is landing at an airport. The plane has a massive amount of kinetic energy due to it's motion. When the plane lands, it activates its brakes, causing it to slow down and eventually stop. The kinetic energy that the plane had is now gone. In keeping with the Law of Conservation of Energy, which of the following is the most likely explaination of what happened to that energy?
The brakes used a coil system to convert the kinetic energy into potential energy stored in the brakes
The kinetic energy of the plane gets pushed into the air in front of it due to drag forces, causing the air to move, thus transferring the kinetic energy from the plane to the air
The brakes create friction, which transformed the kinetic energy to heat energy that was dissipated to the surroundings
The kinetic energy is being converted into sound energy by the loud engines of the plane
Ce clasă ești sa văd daca te pot ajuta
A 14-gauge copper wire of diameter 1.628 mm carries a current of 12.5 What is the potential difference across a 2.00 - m length of the wire? *p=1.47x10^-8
Answer:
[tex]V=1.76\times 10^{-4}\ V[/tex]
Explanation:
Given that,
The diameter of a wire, d = 1.628 mm
Radius, r = 0.814 mm = 0.000814m
Current, I = 12.5 mA
The length of the wire, l = 2m
The resistivity of the wire, [tex]\rho=1.47\times 10^{-8}\ \Omega-m[/tex]
We need to find the potential difference across the wire. We know that the resistance of the wire is given by :
[tex]R=\rho\dfrac{l}{A}[/tex]
Also, V = IR
[tex]\dfrac{V}{I}=\rho\dfrac{l}{A}\\\\V=\dfrac{\rho l I}{A}\\\\V=\dfrac{1.47\times 10^{-8}\times 2\times 12.5\times 10^{-3}}{\pi \times (0.000814)^2}\\\\V=1.76\times 10^{-4}\ V[/tex]
So, the potential difference of the wire is [tex]1.76\times 10^{-4}\ V[/tex].
Write a short paragraph that explains how a sport using a ball would be played differently on a planet of your choice. For example, how would gravity affect a basketball game on Saturn? Or how would gravity affect a baseball game on Mercury?
(Doesnt have to be a full paragraph answer I just need a gist of what it is)
on a different planet I would play a sport similar to soccer. The main difference is that there is zero gravity. To win the game u have to get the ball into the other person's net first.
Explanation:
I was just bored
2. What kinds of statistics are used in sports? In a paragraph explain your answer with examples
from different sports.
Answer: Sports Illustrated noted that analytics in a sport such as a football is widely used to manage injury prevention. Basketball coaches make use of statistics such as field-goal attempts, effective field goal percentage, free throw attempts, and free throw percentages.
Explanation: BRAINLEST?
PLEASE HELPPPPP!!!!!!!!!
An archer defending a castle is on an 15.5 m high wall. He shoots an arrow straight down at 22.8 m/s. How much time does it take to reach the ground? (Unit = s) Watch your minus signs!
Answer:
about 602 milliseconds
Explanation:
The motion can be approximated by the equation ...
y = -4.9t^2 -22.8t +15.5
where t is the time since the arrow was released, and y is the distance above the ground.
When y=0, the arrow has hit the ground.
Using the quadratic formula, we find ...
t = (-(-22.8) ± √((-22.8)^2 -4(-4.9)(15.5)))/(2(-4.9))
= (22.8 ± √823.64)/(-9.8)
The positive solution is ...
t ≈ 0.60195193
It takes about 602 milliseconds for the arrow to reach the ground.
I can't understand
like which energy changes are involved
which energy it was first and which it was converted into
Answer:
turtle
Explanation:
A ball of mass 12 kg is released from a height of 2.5 m
find the gravitational potential energy of the ball at point A
and when it reach the ground.
then deduce the kinetic energy of the ball once it reach the ground
(use g=10 N/kg) * 5
Answer:
300 J
Explanation:
From conservation of energy;
Gravitational potential energy at top = Kinetic Energy at bottom
mgh = ½mv²
We are given;
Mass; m = 12 kg.
Height; h = 2.5 m
g = 10 m/s²
Thus;
mgh = 12 × 2.5 × 10 = 300 J
Since mgh = Kinetic Energy at bottom.
Thus; kinetic energy of the ball once it reach the ground = 300 J
The resistance of 3A and 12V