Answer:
The answer is: Plants and animals exchange carbon dioxide and oxygen with the atmosphere.
Explanation:
Got the answer right.
A ceiling fan with 90-cm-diameter blades is turning at 64 rpm . Suppose the fan coasts to a stop 28 s after being turned off. What is the speed of the tip of a blade 10 s after the fan is turned off
Answer:
the speed of the tip of a blade 10 s after the fan is turned off is 16.889 m/s.
Explanation:
Given;
diameter of the ceiling fan, d = 90 cm = 0.9 m
angular speed of the fan, ω = 64 rpm
time taken for the fan to stop, t = 28 s
The distance traveled by the ceiling fan when it comes to a stop is calculated as;
[tex]d = vt = \omega r\times t= ( \frac{64 \ rev}{\min} \times \frac{2 \pi \ rad}{rev} \times \frac{1 \min}{60 \ s} \times 0.9 \ m) \times 28 \ s\\\\d = 168.89 \ m[/tex]
The speed of the tip of a blade 10 s after the fan is turned off is calculated as;
[tex]v = \frac{d}{t} \\\\v = \frac{168.89}{10} \\\\v = 16.889 \ m/s[/tex]
Therefore, the speed of the tip of a blade 10 s after the fan is turned off is 16.889 m/s.
A 10.0-g bullet is fired into, and embeds itself in, a 1.95-kg block attached to a spring with a force constant of 23.9 N/m and whose mass is negligible. How far is the spring compressed if the bullet has a speed of 300 m/s just before it strikes the block and the block slides on a frictionless surface
Answer: 0.43 m
Explanation:
Given
mass of bullet [tex]m=10\ gm\approx 0.01\ kg[/tex]
mass of block [tex]M=1.95\ kg[/tex]
The Force constant of spring is [tex]k=23.9\ N/m[/tex]
Speed of bullet is [tex]u=300\ m/s[/tex]
Conserving the energy i.e. kinetic energy of the bullet and box is converted into Elastic potential energy of spring
[tex]\Rightarrow \dfrac{1}{2}(M+m)v^2=\dfrac{1}{2}kx^2[/tex]
Conserving linear momentum
[tex]\Rightarrow mu=(M+m)v\\\\\Rightarrow v=\dfrac{mu}{M+m}[/tex]
Put the value of [tex]v[/tex] we get
[tex]\Rightarrow x=mu\sqrt{\dfrac{1}{k(M+m)}}\\\Rightarrow x=0.01\times 300\sqrt{\dfrac{1}{23.9(0.01+1.95)}}\\\Rightarrow x=3\sqrt{\dfrac{1}{46.844}}=\dfrac{3}{6.844}=0.43\ m[/tex]
Thus, spring will be compressed to a distance of [tex]0.43\ m[/tex]
A reaction occurs when a compound breaks down. This reaction has one reactant and two or more products. Energy, as from a battery, is usually needed to break the compound apart.
Answer:
decomposition
Explanation:
A motorist is driving at 15 m/s when she sees that a traffic light 315m ahead has just turned red. She knows that this light stay red for 25 s, and she wants to be 20 m from the ligt when it turns green again. Taht way, she will still be able to stop if the light stays red longer than expected. She applies the brake gradually such that her acceleration is ax(t)= c + bt, where c and b are constant. Assume she starts with a constant speed at the origin.
Find the values of c a b and any other unknown constants in order to answer the following questions.
1. Given the motorist's acceleration as a function of time, what are her position and velocity fucntions? - Do not use numbers for any constant here. Only derive the position and velocity functions.
2. What is her speed as she reaches the light?
Answer:
1) x = x₀ + vot - ½ c t² - 1/6 bt³, v = v₀ - ct - ½ b t²
2) v₁ = 5.25 m/s, v₂ = -8 m/s
Explanation:
1) For this exercise, the relationship of the body is not constant, so you must use the definition of speed and position to find them.
acceleration is
a = c + bt
a) the relationship between velocity and acceleration
a = [tex]\frac{dv}{dt}[/tex]
dv = -a dt
The negative sign is because the acceleration is contrary to the speed to stop the vehicle.
we integrate
∫ dv = - ∫ a dt
∫ dv = -∫ (c + bt) dt
v = -c t - ½ b t²
This must be valued from the lower limit, the velocity is vo, up to the upper limit, the velocity is v for time t
v - v₀ = -c (t-0) - ½ b (t²-0)
v = v₀ - ct - ½ b t²
b) the velocity of the body is
v = [tex]\frac{dx}{dt}[/tex]
dx = v dt
we replace and integrate
∫ dx = ∫ (v₀ - c t - ½ bt²) dt
x-x₀ = v₀ t - ½ c t² - ½ b ⅓ t³
Evaluations from the lower limit the body is at x₀ for t = 0 and the upper limit the body is x = x for t = t
x - x₀ = v₀ (t-0) - ½ c (t²-0) + [tex]\frac{1}{6}[/tex] (t³ -0)
x = x₀ + vot - ½ c t² - 1/6 bt³
2) The speed when you reach the traffic light
Let's write the data that indicates, the initial velocity is vo = 15 m / s, the initial position is xo = 315m, let's use the initial values to find the constants.
t = 25 s x = 20
we substitute
20 = 315 + 15 25 - ½ c 25² - 1/6 b 25³
0 = 295 + 375 - 312.5 c - 2604.16 b
670 = 312.5 c + 2604.16 b
we simplify
2.144 = c + 8.33 b
Now let's use the equation for velocity,
v = v₀ - ct - ½ b t²
v = 15 - c 25 - ½ b 25²
v = 15 - 25 c - 312.5 b
let's write our two equations
2.144 = c + 8.33 b
v = 15 - 25 c - 312.5 b
Let's examine our equations, we have two equations and three unknowns (b, c, v) for which the system cannot be solved without another equation, in the statement it is not clear, but the most common condition is that if the semaphore does not change, it follows with this acceleration (constant) to a stop
a = c + b 25
from the first equation
c = 8.33 / 2.144 b
C = 3.885 b
we substitute in the other two
v = 15 - 25 (3.885 b) - 312.5 b
v = 15 - 409.6 b
final acelearation
a = 28.885 b
let's use the cinematic equation
[tex]v_{f}^2[/tex]= v² - 2 a x
0 = v² - 2a 20
0 = v² - (28.885b) 40
v² = 1155.4 b
we write the system of equations
v = 15 - 409.6 b
v² = 1155.4 b
resolve
v²= 1155.4 ( [tex]\frac{15 -v }{409.6}[/tex] )
v² = 2.8 ( 15 -v)
v² + 2.8 v - 42.3 = 0
v= [ -2.8 ±[tex]\sqrt {2.8^2 + 4 \ 42.3) }[/tex] ]/2 = [-2.8 ± 13.3]/2
v₁ = 5.25 m/s
v₂ = -8 m/s
A stream moving with a speed of 0.5 m/s reaches a point
where the cross-sectional area of the stream decreases to
one-fourth of the original area. What is the water speed in
this narrowed portion of the stream?
Explanation:
hi I like help but I couldn't
In high air pressure the molecules are
A-Warm and moving fast
b-Close together and moving slowly
c-far apart and moving slowly
d-hot and moving rapidly
Q1what is pinhole camera?
someone please help I can mark brainless
1. When an unbalanced force acts on an object,
O the object remains at rest
the weight of the object decreases.
O the object's motion changes.
the inertia of the object increases.
A hook in boxing primarily involves horizontal flexion of the shoulder while maintaining a constant angle at the elbow. During this punch, the horizontal flexor muscles of the shoulder contract and shorten at an average speed of 75 cm/s. They move through an arc length of 5 cm during the hook, while the fist moves through an arc length of 100 cm. What is the average speed of the fist during the hook
Answer:
average speed of the fist during the hook = 15 m/s or 1500 cm/s
Explanation:
We are given;
Speed of shoulder contraction, v_s = 75 cm/s = 0.75 m/s
Distance moved through the arc length by shoulder, d_s = 5 cm = 0.05 m
Distance moved by the fist, d_f = 100 cm = 1 m
Now, we are to find the average speed of the fist during the hook; v_f
Thus can be gotten from proportion;.
d_f/d_s = v_f/ v_s
Making V_f the subject, we have;
v_f = (d_f × v_s)/d_s
Thus;
v_f = (1 × 0.75)/0.05
v_f = 0.75/0.05
v_f = 15 m/s
Which of the following is true for the entropy of the universe?
A It is always decreasing.
B It is always increasing.
C It is always negative.
D It is always a constant.
Answer:
B It is always increasing.
Explanation:
In Physics, entropy can be defined as the tendency or ability of a substance to reach maximum disorder i.e to be randomly distributed.
This ultimately implies that, entropy is a thermodynamic quantity that measures the degree of maximum disorder or randomness of a system.
The S.I unit used for the measurement of the degree of maximum order or randomness of a system is Joules per Kelvin (JK¯¹). An example of entropy is the mixing of ideal gases.
Generally, the entropy in an irreversible process always increases and as such the change in entropy has a positive value.
Hence, the entropy of the universe is always increasing because its energy flow is considered to be in a downward direction rather than upward i.e from a hot region to a cold region; making the energy to be evenly distributed.
3
How does the electrical conductivity of metals
and metalloids change with an increase in
temperature?
Answer:
In metals there are free electrons at normal temperature so when we increase temperature it resistivity gets increases,so conductivity decreases,while in semiconductor the electrons are not free so when we increase the temperature the covalent bonds begin to break and the electron becomes free so conductivity get.
Explanation:
(will give brainliest to whoever answers first and explains reasoning) A 10kg object is spun around in a circle with a centripetal acceleration of 3.5m/s^2. What is the centripetal force acting on the object?
Answer:
35 N
Explanation:
F = ma
centripetal force = 10(3.5) = 35 N
which one is odd copper,plastic,rubber
Answer:
It's plastic.
trust me it's plastic, i've rad it somewhere.
All of them have something that's not like the others.
-- Rubber is the only one on the list that has two repeated letters.
-- Plastic is the only one on the list thagt has no repeated letters.
-- Plastic is the only one on the list that has no 'r' in its name.
-- Copper is the only one on the list that is an element, not a compound.
-- Copper is the only good electrical conductor on the list.
-- Plastic is the only one on the list with more than six letters in its name.
-- Rubber is the only one on the list with no 'p' in its name.
-- Plastic is the only one on the list that doesn't end in "-er".
A motorcycle is traveling along a highway at 29 m/s. How far does the motorcycle travel in 18 s?
Answer:
the motorcycle travels 522 miles in 18 seconds Explanation: 29 x 18 is 522 I'm pretty sure that's what it was asking but I don't know
Define the term pressure
Answer:
Pressure is the perpendicular force applied per unit area.
When grip strength increases:
a. action potential voltage increases.
b. action potential frequency decreases.
c. action potential frequency increases.
d. action potential frequency increases.
e. the number of active motor units increases.
Answer:
e. the number of active motor units increases.
Explanation:
There is a direct relationship between the number of active motor units and the grip strength in a given scenario. For example, increase in the grip strength leads to increase in the number of active motor units. In the other-hand, the decrease in grip strength leads to the decrease in the number of active motor units.
Cells use nutrients and oxygen to supply the body with the energy it needs. What three-body systems are working together in this situation?
A
nervous, digestive, and circulatory systems
B
digestive, circulatory, and excretory systems
C
circulatory, immune, and respiratory systems
D
digestive, respiratory, and circulatory systems
Answer:
The respiratory system provides oxygen for cells, while the circulatory system transports oxygen to cells.
Explanation:
so the answer is D
In a double-slit experiment, light from two monochromatic light sources passes through the same double slit. The light from the first light source has a wavelength of 640 nm. Two different interference patterns are observed. If the 10th order bright fringe from the first light source coincides with the 12th order bright fringe from the second light source, what is the wavelength of the light coming from the second monochromatic light source
Answer:
533.33 nm
Explanation:
Since dsinθ = mλ for each slit, where m = order of slit and λ = wavelength of light. Let m' = 10 th order fringe of the first slit of wavelength of light, λ = 640 nm and m"= 12 th order fringe of the second slight of wavelength of light, λ'.
Since the fringes coincide,
m'λ = m"λ'
λ' = m'λ/m"
= 10 × 640 nm/12
= 6400 nm/12
= 533.33 nm
help me pls
An object accelerates if it:
a.) changes the direction of its velocity but not the magnitude
b.)changes the magnitude of the velocity but not the direction
c.)changes its speed
d.) all of the above
e.) none of the above
Answer:
D
Explanation:
A girl weighing 45kg is standing on the floor, exerting a downward force of 200N on the floor. The force exerted on her by the floor is ..............
Select one:
a.
No force exerted
b.
Less than 2000N
c.
Equal to 200 N
d.
Greater than 200 N
Answer:
c.
Equal to 200 N..........
Linearly polarized light whose Jones vector is [0 1] (horizontally polarized) is sent through a train of two linear polarizers. The first is oriented with its transmission axis at 45 degrees and the second has its transmission axis vertical. Show that the emerging light is linearly polarized in the vertical direction; that is, the plane of polarization has been rotated by 90 degrees.
Answer:
Following are the solution to the given question:
Explanation:
The input linear polarisation was shown at an angle of [tex]2 \mu[/tex]. It's a very popular use of a half-wave plate. In particular, consider the case [tex]\mu = 45 \pm[/tex], at which the angle of rotation is [tex]90\pm[/tex]. HWP thereby provides a great way to turn, for instance, a linear polarised light that swings horizontally to polarise vertically. Illustration of action on event circularly polarized light of the half-wave platform. Customarily it is the slow axis of HWP that corresponds to either the rotation. Note that perhaps the vector of polarization is "double-headed," i.e., the electromagnetic current swinging back and forward in time. Therefore the turning angle could be referred to as the rapid axis to reach the same result. Please find the attached file.
Use the drop-down menus to complete each statement about tornado safety.
Before a tornado warning occurs, you should
✔ have a disaster plan ready.
If you’re indoors during a tornado, you should
✔ go to the basement.
If you’re outdoors during a tornado, you should
✔ lie in a ditch or low-lying area.
Answer:
correct tysmm
Explanation:
Even in the most advanced circuits, we cannot oscillate electrons back and forth at that rate through wires. But we can oscillate charges back and forth quickly enough to broadcast TV using radio wave signals. At what frequency do the electronics at the TV station need to have the charges oscillate back and forth on a TV broadcast antenna to transmit a typical TV signal (say a radio wave transmission signal with a wavelength of 1 meter)
Answer:
the oscillations of the electrons must be in the 10⁸ Hz = 100 MHz range
Explanation:
The speed of a wave of radio, television, light, heat, all are manifestations of electromagnetic waves that are oscillations of electric and magnetic fields that support each other, the speed of all these waves is the same and the vacuum is equal to c = 3 108 m / s
All waves have a relationship between the speed of the wave, its frequency and wavelength
c = λ f
f = c /λ
for this case lam = 1 m
f = 3 10⁸/1
f = 3 10⁸ Hz
the oscillations of the electrons must be in the MHz range
It should be clarified that the speed of light in air is a little lower
n = c / v
v = c / n
the refractive index of vacuum is n = 1 and the refractive index of air is n = 1.000002
What are some possible factors that can be the X
and Y axis of a motion graph?
Answer:
x-Speed/velocity
y-time.
Explanation:
because Speed is a rate of change of distance while time how long it takes a a car to move to a specific point
Do blood cells have a nuclei? Describe the shape of blood platelets.
Answer: Mature red blood cells don't have nuclei.
Explanation: " Platelets are irregularly shaped, have no nucleus, and typically measure only 2–3 micrometers in diameter. "
Hope this Helps!!
__________ and __________ both heavily relied on dream analysis in their treatment of patients. A. Alfred Adler . . . Albert Ellis B. Alfred Adler . . . Carl Jung C. Sigmund Freud . . . Carl Jung D. Sigmund Freud . . . Alfred Adler
Answer:
C. Sigmund Freud . . . Carl Jung
Explanation:
edge 2021
C.Sigmund Freud and Carl Jung both heavily relied on dream analysis in their treatment of patients.
What is Freud most famous for?Freud is well-known for inventing and developing the approach of psychoanalysis; for articulating the psychoanalytic idea of motivation, intellectual infection, and the structure of the unconscious; and for influencing medical and popular conceptions of human nature by using positing both everyday and strange thought.
Sigmund Freud was an Austrian neurologist who's perhaps maximum known as the founding father of psychoanalysis. Freud advanced a fixed of therapeutic strategies centered on communication therapy that worried the use of techniques that include transference, loose affiliation, and dream interpretation.
Learn more about Sigmund Freud here: https://brainly.com/question/2706543
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write the definition
Heredity, Dominant allele, recessive allele, probability, genotype, phenotype
Explanation:
Heredity: The passing on of physical or mental characteristics genetically from one generation to another.
Dominant allele: In genetics, dominance is the phenomenon of one variant of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome. The first variant is termed dominant and the second recessive.
Answer:
Heredity: the passing on of physical or mental characteristics genetically from one generation to another.
Dominant Allele: a variation of a gene that will produce a certain phenotype, even in the presence of other alleles.
Recessive Allele: a variety of genetic code that does not create a phenotype if a dominant allele is present.
Probablity: used to measure the chance or likelihood of an event to occur.
Genotype: an organism's complete set of genetic material
Phenotype: the set of observable characteristics of an individual resulting from the interaction of its genotype with the environment.
Four rods that obey Hooke's law are each put under tension.
a. A rod 50.0 cm long with cross-sectional area 1.00 mm2 and with a 200 N force applied on each end.
b. A rod 25.0 cm long with cross-sectional area 1.00 mm2 and with a 200 N force applied on each end.
c. A rod 20.0 cm long with cross-sectional area 2.00 mm2 and with a 100 N force applied on each end. Order the rods according to the tensile stress on each rod, from smallest to largest.
Order the rods according to the tensile stress on each rod, from smallest to largest.
1. c < b < a
2. a=b
3. a< b < c
4. c
Answer:
c < a<=b
Explanation:
Tensile stress = (force) /Area
for A:
Tensile stress = 200/1 =200N/mm²
For B:
Tensile stress = 200/1 =200N/mm2
For C:
Tensile stress = 100/2 =50N/mm²
Ranking from smallest to largest we have;
C<A<=B which is option 4
Select the correct answer.
Why are the requirements to become a congressional representative and a senator different?
A.
The framers didn’t want senators to worry about their constituents as often as representatives do.
B.
The framers gave senators more lawmaking powers and responsibilities than representatives.
C.
The framers wanted senators to be more mature and more experienced than representatives.
D.
The framers thought senators and representatives should have reasons to argue with each other.
The framers wanted senators to be more mature and more experienced than representatives. (C)
Answer:
C -> The framers wanted senators to be more mature and more experienced than representatives.