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.
When we say the energy in a system remains "constant" what we really
mean is...
1 point
the total amount of energy goes up
the total amount of energy remains the same
the total amount of energy goes down
the speed remains the same
of the following is NOT a form of energy?
The total amount of energy remains the same.
A 1 kg block with initial velocity 4 m/s collides elastically with a stationary 2 kg block. After the collision, the 1 kg block has a velocity of -1.33 m/s. Determine the speed of the 2 kg block after the collision.
Answer:
v₂ = 2,665 m / s
Explanation:
This is an exercise of conservation of the momentum, we define a system formed by the two cars, so that the forces during the collision are internal and the moment is conserved.
Initial instant. Before the crash
p₀ = m v_o
Final moment. Right after the crash
p_f = m v₁ + M v₂
where the first car uses subscript 1 and has a mass m = 1 kg and the second car uses the subscript 2 with a mass M = 2kg
how the moment is preserved
p₀ = p_f
m v_o = m v₁ + M v₂
They indicate that the collision is elastic, therefore the kinetic energy is conserved, the velocity of the first car is v1 = -1.33 me / S
v₂ = [tex]\frac{ m ( v_o - v_1)}{M}[/tex]
we calculate
v₂ = [tex]\frac{ 1 ( 4 + 1.33)}{2}[/tex]
v₂ = 2,665 m / s
Calculate the force of gravity between two protons located 1m apart 1.7x10-27kg charge of proton is +1.6x10-19c
Answer:
87, not very hard but u have to keep trying ❤❤❤❤❤❤❤
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
PLEASE HELP ME! do tectonic plates play a major or minor role in the ROCK CYCLE
Answer: All igneous rocks the basis of the rock cycle is formed by plate tectonics. ... This movement from igneous to sedimentary back to igneous is a major part of the rock cycle. The heat from the mantle that fuels plate tectonics causes both igneous and sedimentary rocks to be turned into metamorphic rocks.
Explanation: BRAINLEST?
A 1000kg truck is moving at a velocity of 4m/s what is it's momentum?
Answer:
4000 kg m/s
Explanation:
p=mv
p = momentum in kg m/sm = mass in kgv = velocity in m/ssubstitute values into the formula above to get:
p=1000x4
p=4000 kg m/s
1. When is the object in motion?
Answer:
An object is in motion when its distantance from another object is changing
Answer:
when an object is moving..
Explanation:
mark me as brainlist
9. In a closed circuit made of a battery, a wire, a lightbulb, and a switch which part's main responsibility is allowing electricity to flow over a distance?
A: battery
B: light bulb
C: switch
D: wire
Answer:
d
Explanation:
Answer:
D: wire
Explanation:
do dendrites take in information while the axon takes information away from the cell body
Answer:
Yes
Explanation:
Dendrites bring electrical signals to the cell body and axons take information away from the cell body.
What type of wave interaction causes dead spots?
Refraction
Reflection
Constructive Interference
Destructive interference
Can sombody help me out real quick?
Dogs can hear sounds that we can't. Research dogs and find out what frequencies they can hear. Write down what you find out. Using what you just learned, write a short story on what it might be like to be a dog. Include a description of what you might hear and how it might affect you if you were a dog. Your story can be fictional or nonfictional - it can be whatever you want it to be! Take some time to listen to sounds in your environment. Make a list of ten sounds, ranking them from the highest pitch to the lowest. Write a couple of sentences describing whether this was easy or difficult and why.
Answer:
I did this essay before, its not hard. Just read through it carefully and you'll figure it out. or just ask you mom, dad, guardian, or teacher for help
The human ear can hear the frequency range of 20 Hz to 20 kHz and dogs can hear up to the range of 40Hz up to 50,000Hz or even 60,000Hz. Compared to humans, dogs have a significantly wider range of hearing.
What is sound?Sound is a mechanical disturbance that travels through an elastic medium and disrupts an equilibrium condition. It is also feasible to define sound solely subjectively, as that which is perceived by the ear.
Although this definition lacks clarity and is overly pedantic because it is necessary to discuss noises that cannot be heard by the human ear, such as those made by dog whistles or sonar devices.
Given:
Dogs can hear sounds that we can't,
While small toddlers can hear noises exceeding 20,000 Hertz (Hz), the average adult cannot. (The frequency of a sound is measured in Hertz, and the greater the frequency, the higher pitched the sound.) Dogs, on the other hand, are capable of hearing frequencies between 40Hz up to 50,000Hz or even 60,000Hz.
To know more about sound:
brainly.com/question/29707602
#SPJ2
What is elastic potential energy and give and a example
Answer:
Many objects are designed specifically to store elastic potential energy, for example: The coil spring of a wind-up clock. An archer's stretched bow. A bent diving board, just before a divers jump
Explanation:
Answer:
Elastic Potential Energy is stored in elastic items.
A example of Elastic Potential Energy is a rubber band. When you stretch it, and it shoots off your finger. Where the rubber band gives off Elastic Potential Energy, is when you stretch it on your fingers, before you let it go.
DESPERATE WILL GIVE BRAINLIST AND THANKS (PLZ HURRY)
Which statement is FALSE about Redi & Pasteur’s experiments?
Redi’s independent variable was jar coverings.
Pasteur’s independent variable was boiled broth.
Pasteur’s dependent variable was the growth of microbes (bacteria).
Both experiments were conducted gather evidence to disprove spontaneous generation.
Answer:
B
Explanation:
Its not litteral
WHAT ARE THE RISK OF BLADED TOOLS
Answer: Cuts and Scrapes
Explanation:
If something happens you could be hospitalized. You could get an amputation
A car of mass 150 kg is riding down at constant velocity What is the friction force?
Answer:
I think it's b
Explanation:
friction is the opposite direction of the object do it's definitely left something
* why does one prefesumbrella
even in summer.
Answer:
black umbrella provides a better shade
Explanation:
This is because a black umbrella provides a better shade than a white umbrella . Absorption of more light energy from the sun by the black umbrella does not matter because our body is not in touch with the umbrella .
You have a working electrical series circuit with three light bulbs, then 1 bulb burns out. Describe how electric current flows through the series circuit after 1 of the 3 bulbs burns out?
Answer:
NARUTO IS A DIME GOD
Explanation:
Help, please!!!!!
I just need help putting the vocab word in the box where it belongs.
here's the first part but for the 2nd one all I know is that the word "compression" goes on the spirals that are closer together.
hope this helps!
How does kinetic energy change if you double the steed?
PLS HELP!!! Response: Develop a unique example (not posted on the discussion board by anyone else) and calculate the resultant displacement between two points when there are two legs or distinct parts to the trip. Include the displacement of each leg of the trip as well as the resultant displacement of the entire trip. Don't forget: include both the direction and the magnitude as part of the displacement. Research the actual distance between these two points on the globe. Compare the resultant displacements and account for the error. Don't forget: include both the direction and the magnitude as part of the displacement.
Answer:
he is the first person can be 3in and a 6man is the best not a man of the hartford
helppppppppppppppppppppppppppppppppppppppppppppppp
Which model of the solar system is shown here?
O O
A. The heliocentric model B. The spherical model
O
C. The geocentric model
O
D. The universal model
Answer:
A
My logic:
Heliocentrism is the astronomical model in which the Earth and planets revolve around the Sun at the center of the Universe.
Hope this helps!
What is the charge on an object that experiences a force of 5 Newtons in an electric field of 50 Newtons per coulomb?
Answer:
Explanation:
F = qE
F is the force in Newtons
q is the test charge
E is the electrical field produced by the source charge
[tex]5=q(50)\\q=1*10^-^1Coulombs[/tex]
The magnitude of charge on the object is of 0.1 C.
Given Data:
The magnitude of electric field is, E = 50 N/C.
The magnitude of Electric force is, F = 5 N.
The region where any particle feels the effect of electric force on itself, due to other charged entities, is known as Electric field. And the relation between the electric force and electric field is given as,
F = E × q
Here,
q is the magnitude of charge on the object.
Solving as,
q = F/E
q = 5 / 50
q = 0.1 C
Thus, we can conclude that the magnitude of charge on the object is of 0.1 C.
Learn more about the electric field here:
https://brainly.com/question/8971780
which system of units is used by only a small number of countries in the world, including the u.s
Answer:
imperial system
Explanation:
Answer:
british system
Explanation:
A P E X
I AM TIMED !! 30 POINTS Which is the smallest possible particle of an element?
O molecule
O atom
O compound
O matter
Answer:
atoms
Explanation:
they are the smallest
What is the frequency of a wave with a wavelength of 12 meters and a velocity of 4 m/s?
Answer:
0.33 hz
Explanation:
the formula for the frequency in this situation is f=v/wavelength
Given that the frequency of an Em wave is 4THz, what is its wavelength? a) 75,000um b) 75,000nm c) 75,000pm d) 75,000A
Answer:
λ = 75 µm, correct is A
Explanation:
In waves, speed is related to wavelength and frequency
c = λ f
λ = c / f
in this exercise indicate the frequency of rationality
f = 4 THz = 4 10¹² Hz
let's calculate
λ = 3 10⁸/4 10¹²
λ = 7.5 10⁻⁵ m = 75 10⁻⁶ m
λ = 75 µm
5 points
What did Alfred Wegener think happens during Continental Drift?
A. Continents move
B. The mantle warms
C. Convection Stops
D. Continents freeze
Answer:
Continents move
Explanation:
What is the length of decay of carbon-14?
a.
A couple days
b.
A couple hours
c.
A couple seconds
d.
A few thousand years
Answer:
My answer will be (D) . A few thousand years
Explanation:
Carbon-14 is a radioactive isotope of carbon, containing 6 protons and 8 neutrons, that is present in the earth's atmosphere in extremely low concentrations.2
It is naturally produced in the atmosphere by cosmic rays (and also artificially by nuclear weapons), and continually decays via nuclear processes into stable nitrogen atoms.
Suppose we have a sample of a substance containing some carbon-14. Let m be the mass of carbon-14 in nanograms after t years. 3
It turns out that, if the sample is isolated, then m and t approximately 4 satisfy the differential equation
dmdt=−0.000121m.
Suppose our sample initially contains 100 nanograms of carbon-14. Let's investigate what happens to the sample over time.
First, we can solve the differential equation. Since m has a continuous decay rate of −0.000121, a general solution to the differential equation is
m(t)=Ce−0.000121t,
where C is a constant. Substituting the initial condition t=0, m=100 gives C=100, so
m(t)=100e−0.000121t.
With this formula, we can calculate the amount m of carbon-14 over the years.
Mass of carbon-14 in sample
t (years) m (ng to 4 decimal places)
0 100.0000
100 98.7973
1000 88.6034
2000 78.5056
5000 54.6074
10 000 29.8197
20 000 8.8922
Every year, the mass m of carbon-14 is multiplied by e−0.000121≈0.999879. After 100 years, 98.7973 nanograms still remain. After 1000 years, we still have 88.6034 nanograms. But after 5000 years, however, almost half of the carbon-14 has decayed.
Graph showing the decay of 100 nanograms of Carbon-14.
Detailed description
half-life of carbon-14
Example
How long does it take for precisely half of the carbon-14 in the sample to decay; that is, when does m=50? Give the answer to three significant figures.
Solution
The mass of carbon-14 in our sample is given by
m(t)=100e−0.000121t.
So we solve 50=100e−0.000121t, which gives e−0.000121t=12. Hence,
t=loge12−0.000121≈5730 years (to three significant figures).
The time period calculated in this example is called the half-life of carbon-14. In fact over any period of 5730 years, the amount of carbon-14 in an isolated sample will decay by half. This fact is used in radiocarbon dating to determine the age of fossils up to 60 000 years old. Roughly speaking, while an organism is alive, its interactions with its environment maintain a constant ratio of carbon-14 to carbon-12 in the organism; but after it dies, the carbon-14 is no longer replenished, and the ratio of carbon-14 to carbon-12 decays in a predictable way. (See Wikipedia Open new window for more on radiocarbon dating.)
Exercise 1
Explain why the mass of carbon-14 in the sample is given (approximately) by
m(t)=100(12)t5730,
and hence explain why the amount of carbon-14 in the sample decays by half over any period of 5730 years.
Half-life in general
In general, whenever a quantity x(t) obeys an exponential decay equation
x(t)=Cekt,
where the continuous decay rate k is negative, then the quantity x has a half-life T. After any time period of length T, the quantity x decreases by half. Let us see why.
As k is negative, the factor ekt decreases from 1 (at t=0) towards 0 (as t approaches ∞). Therefore there is a time t=T such that
ekT=12.
We now solve for T and obtain
kT=loge12=−loge2,
so
T=−1kloge2.
This T is the half-life. From time t=0 to time t=T, the factor ekt decreases from e0=1 to ekT=12, that is, decreases by half. Similarly, over any time period of length T, the term ekt decreases by half. 5
Note that, when k=−0.000121, we obtain T=5730, in agreement with our calculation for carbon-14.
Hope this work
If I'm wrong I'm sorry
If I'm right thank you (brainliest plz )
how high is the pole from which the lamp fell freely if it hits the ground at a speed of 15 m/s
Answer & Explanation:
The acceleration due to gravity is about 10 m/s^2.
That means a the speed of a falling object will increase by 10 m/s every second that it falls.
We know that the lamp hits the ground at 15 m/s.
That means the lamp has been falling for
[tex]\frac{15 m/s}{10 m/s^{2} } = 1.5 s[/tex]
Now we use the formula [tex]h = \frac{1}{2} gt^{2}[/tex] to calculate the height, where
h is the height
g is the acceleration due to gravity and
t is the time taken to fall a height of h.
h = 1/2 x 10 x 1.5^2 = 11.25 m
Hurry pls I need help
Answer:
away from each other
Explanation:
Thus, two negative charges repel one another, while a positive charge attracts a negative charge. The attraction or repulsion acts along the line between the two charges. The size of the force varies inversely as the square of the distance between the two charges.