Answer:
13. (i) The magnitude of the force that is pressing the lawn-mower directly into the ground is 25 N
(ii) The magnitude of the effective force that moves the mower forward is approximately 43.3 N
(iii) Because there are no net downward force acting on the lawn-mower
Explanation:
13. The given force pushing the lawn-mower = 50 N
The angle at which the force acts = 30° to the ground
The component of the pushing force are;
(i) The magnitude of the force that is pressing the lawn-mower directly into the ground = The vertical component of the pushing force
The vertical component of the pushing force, [tex]F_y[/tex] = 50 N × sin(30°) = 25 N
∴ The magnitude of the force that is pressing the lawn-mower directly into the ground = [tex]F_y[/tex] = 25 N
(ii) The magnitude of the effective force that moves the mower forward = The horizontal component of the pushing force
The horizontal component of the pushing force, Fₓ = 50 N × cos(30°) = 25·√3 N ≈ 43.3 N
∴ The magnitude of the effective force that moves the mower forward = 25·√3 N ≈ 43.3 N
(iii) The lawn mower moves forward and not downwards because according to Newton's first Law of motion, the lawn-mower moves forward because it is being acted on by a net forward directed horizontal force
However, according to Newton's third law, the reaction of the ground is equal to the weight of the lawn mower, therefore, there are no net vertical force acting on the lawn-mower, such that the lawn-mower remains in the initial horizontal level and does not move downward into the ground.
What is density? Write a formula by showing the relation of mass density and volume
Answer: below
Explanation: Density, mass of a unit volume of a material substance. The formula for density is d = M/V, where d is density, M is mass, and V is volume
Answer:
Density is defined as the amount of matter contained in unit volume of body
the breakdown of rocks by chemical action of air and water is called
Answer:
Chemical weathering
Explanation:
This changes the molecular structure of rocks and soil. For instance, carbon dioxide from the air or soil sometimes combines with water in a process called carbonation. This produces a weak acid, called carbonic acid, that can dissolve rock.
How would the model change as the atom forms bonds? The third shell would have eight electrons after the atom gains seven electrons to fill the outermost shell. The third shell would be empty so that the eight electrons in the second level would be outermost after the atom loses one electron. The first and third shells would be empty so that the atom would have eight electrons in its remaining shell after the atom loses three electrons. The first shell would have two electrons and the second shell would have six electrons after the atom loses three electrons.
Answer:
The third shell would be empty, so the eight electrons on the second level would be the outermost after the atom lost one electron
Explanation:
When an atom is bonded with other atoms, a more stable configuration must be reached, which is why the energy of the molecule is less than the energy of the individual atoms, for this to happen in general, electrons are shared or lost and gained in each atom, depending on the electronegative of the same.
If we analyze an atom within the molecule, its last shell is full, in the case of atoms with few electrons in this shell, they are lost and in the case of many electors in this shell, it gains electrons to have eight (8) in total.
When reviewing the different answers, the correct one is:
* The third shell would be empty, so the eight electrons on the second level would be the outermost after the atom lost one electron
Answer: It’s B
Explanation:
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
A fixed source charge particle of 4.1 nC and a second particle with a charge 2.4 nC are separated by a distance of 3.5 cm. What is the electric potential energy between the particles? And if the second particle is released will it move forward or away from the source charge
Answer:
a. 2.53 μJ b. It will move away
Explanation:
a. What is the electric potential energy between the particles?
The electric potential energy U = kq₁q₂/r where k = 9 × 10⁹ Nm²/C², q₁ = 4.1 nC = 4.1 × 10⁻⁹ C, q₂ = 2.4 nC = 2.4 × 10⁻⁹ C and r = distance between charges = 3.5 cm = 3.5 × 10⁻² m.
Substituting the values of the variables into U, we have
U = kq₁q₂/r²
U = 9 × 10⁹ Nm²/C² × 4.1 × 10⁻⁹ C × 2.4 × 10⁻⁹ C/3.5 × 10⁻² m
U = 88.56 × 10⁻⁹ Nm²/3.5 × 10⁻² m
U = 25.3 × 10⁻⁷ Nm
U = 2.53 × 10⁻⁶ Nm
U = 2.53 × 10⁻⁶ J
U = 2.53 μJ
b. And if the second particle is released will it move forward or away from the source charge.
It will move away from the source charge since they have the same sign of charge. Since, opposite charges repel.
Answer:2.5 * 10^6 J away
Explanation:Using the equation PE = 9 * 10^9 * q1 * q2 / r,
where q is charge and r is distance. In this case, the equation would be
9*10^9{(4.1* 10^-9) * (2.4*10^9)/0.035} = 2.5 * 10^6. Both are positive, so they will be away.
A bullet at 800 m/s horizontally hits a target that is 180m away. How far does the bullet fall before it hits the target?
Describe the Geocentric Model of the our solar system.
Answer:
its basically our universe
Explanation:
:) hope this helps
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.
How many electrons per second flow through a wire with a 12pA current?
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
who was the chairman of drafting committe
Rain and wind place which type of load on structures?
A) Dynamic load
B) Soft load
C) Gradual load
D) Static load
a variable that is changed by the researcher is called ___
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
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The illustration shows the forces in Newtons (N) acting on three different blocks. Which
boxes will move under these conditions?
Answer:a
Explanation:because I know
Answer:
B & C
Explanation:
the first block will not move
A rock is thrown horizontally off a cliff with an initial velocity of 15 m/s. How high was the cliff if the rock lands 22 m from the base of the cliff?
Answer:
22 m
Explanation:
Answer:
cliff height = 10.55 m
Explanation:
Remarks
This is one of those questions that defies belief. The final vertical velocity is the same as if you just dropped the rock, which is amazing.Another amazing fact is that the horizontal speed has no acceleration. And amazing fact number three is the the vertical initial speed is 0.And finally, the time taken to go horizontally = time to go vertically.Solution
Time
So the time taken is d = r * t
Remember, this formula can only be used when there is no acceleration.
d = 22 meters
r = 15 m/s
t = ?
t = d / r
t = 22 / 15
t = 1.467
Height of the Cliff
vi = 0 (vertially)
a = 9.8 m/s^2
t = 1.467 seconds The time horizontally and vertically is the same.
d = ?
Formula
d = vi*t + 1/2 a t^2
Solution
d = 0 + 1/2 * 9.8 * 1.467^2
d = 10.55 meters.
PLEASE HELPPPPP!!!!!!!!!
what is hydraulic pressure
The total thrust, expressed in pounds or tons, that the hydraulic-feed mechanism on a drill can impose on a drill string; also, the pressure of the fluid within the hydraulic cylinders, generally expressed in pounds per square inch. Ref: Long.
Hydraulic pressure is the force imparted per unit area of a liquid on the surfaces which it has contact. Liquids are incompressible, and as such, when a load acts
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:
A constant friction force of 21 N acts on a 63-kg skier for 25 s on level snow. What is the skier’s change in velocity?
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.
What will happen to a balloon filled with air when you cool the balloon in ice
Answer:
the volume of balloon decreases by the lower temperature because the gas inside is cool downAunt Mary needs to hang a picture in her bedroom. She uses a hammer to drive the nail into the wall. Find the force exerted by the hammer on the nail if the hammer stays in contact with the nail for 0.5s and has an impulse of 25Ns
Answer:
50N
Explanation:
Impulse = Force × Time
25 = Force × 0.5
Force = 25/0.5
= 50N
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!!
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:
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
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].
List some benefits of Cardiovascular exercise:
Answer:
Aerobic exercise reduces the risk of many conditions, including obesity, heart disease, high blood pressure, type 2 diabetes, metabolic syndrome, stroke and certain types of cancer. Weight-bearing aerobic exercises, such as walking, help decrease the risk of osteoporosis.
Answer:
reduced heart attack chance
Explanation:
cholestrol buildups get destroyed by high pressure blood
uwu
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 5-meter lever has a 4-meter long input arm. If an output force of 500 newtons is attached at one end of the
lever, how much input force must be applied to move the 500-newton output force?
Answer:
125N
Explanation:
500/4=125N