Answer:
A) Δf = - 49 m, B) v (7) = -56 m / s, a = - 8 m / s², C) t = 0.866 s
Explanation:
A) In this exercise ask to find the displacement and the average velocity, give the function of the movement
f (t) = - 4t² +3
and the range of motion 0≤ t ≤ 7
the displacement is
for t = 0
f (0) = 3
for t = 7 s
f (7) = - 4 7² +3
f (7) = -46 m
the total displacement is
Δf = f (7) - f (0)
Δf = -46 - 3
Δf = - 49 m
the average speed is defined as the displacement between the time interval
v = Df / Dt
v = -49 / 7
v = - 7 m / s
B) the speed and acceleration of the end points of the motion
the speed of defined by
v = [tex]\frac{dx}{dt}[/tex]
in this case
v = [tex]\frac{df}{dt}[/tex]
v = -8t
let's calculate
v (7) = -8 7
v (7) = -56 m / s
acceleration is defined by
a = [tex]\frac{dv}{dt}[/tex]
a = - 8 m / s²
acceleration is constant throughout the movement
C) the point where the direction changes.
This point is a point where the position goes from positive to negative, the point f = 0
0 = -4t² +3
t = √¾
t = 0.866 s
3. Do you think Lynn’s (the protagonist)actions were justifiable by her motives? Why or why not? Please help me Bad Genius the movie
Answer:
I do believe her actions were justified.
Explanation:
Due to the school charging extra fee from her father who makes a modest amount as a teacher. There was sum of money involved that could change how he lived and her.
I do not believe her actions where justified
She had a lot going for her. She could have skipped the hardship of helping grace and pass. She could have easily have gotten a good job with a degree and paid back all the debts owed. Alot of troubles could have been avoided just by doing her own thing.
Please help me I’ll mark brainless
Answer:
ITS B NOT A
Explanation:
The nearest neighbor interaction force is of magnitude 481 nanoNewtons, e.g., the magnitude of the force of the leftmost electron on the proton, or the magnitude of the force of any of the three on its nearest neighbor electron. Calculate the size of the net force on the leftmost proton.
Answer:
F = 120.25 10⁻⁹ N
Explanation:
In this exercise, the force between the closest neighbors is indicated by f = 481 10⁻⁹ N, in general between the one-dimensional solid the distances remain the same, if the distance between the first neighbor is d, the distance between the second neighbors is 2d.
For most solids the attractive forces are electrical, therefore force is proportional to the electrical charges and the inverse of the distance squared,
F = [tex]k \frac{q_1 q_2}{r^2}[/tex]
if we call fo the force for the first neighbors
F₀ = k \frac{q_1 q_2}{d^2}
the force for the second neighbors r= 2d
F = k \frac{q_1 q_2}{(2d)^2}
F = F₀ / 4
let's calculate
F = 481 10⁻⁹ / 4
F = 120.25 10⁻⁹ N
3. What were some of the materials use in ancient history times in the
making of the ball?
Answer: Fur stuffed with feathers.
Explanation:
Ball games were popular throughout ancient history but also in the Middle Ages. Many of these games are the forerunners of today's American football and soccer. There are data on almost all continents on how peoples practiced some ball sports in antiquity. The game balls' look was not like today, it was mostly egg-shaped, and the materials for making it were different. The most common material for making the ball was leather, which was filled with feathers.
Why do birds not get shock when they
sit on high power live wire but we do?
Answer:
Their bodies don't conduct electricity like we do.
Explanation:
Answer:
birds dont get shocked because they sit on their talons and their talons are a different type of skin then the rest of their body
Explanation:
Do You think History is the most important subject that deserves first place? Do you see a way that learning history could assist you in your future career?
yes
Explanation:
history is an important class and it helps to you understand what went on in the past so that we can learn from our mistakes and help us grow
Peter, a 100 kg basketball player, lands on his feet after completing a slam dunk and then immediately jumps up again to celebrate his basket. When his feet first touch the floor after the dunk, his velocity is 5 m/s downward; when his feet leave the floor 0.50 s later, as he jumps back up, his velocity is 4 m/s upward. a. What is the impulse exerted on Peter during this 0.50 s
Answer:
Explanation:
Impulse = change in momentum
Initial momentum = mass x initial velocity = 100 x 5 = 500 kg m/s
final momentum = mass x final velocity = 100 x - 4 = -400 ( - ve sign due to reversal of direction )
change in momentum = final momentum - initial momentum
= - 400 - 500 = - 900 kg m/s .
As it is - ve , it acts upwards .
So magnitude of impulse on Perter = 900 kg m/s
If a rock and a feather are dropped in a 98-meter-long tube in which there is a vacuum, which one will hit the bottom first?
The feather will hit the bottom first.
А
B
The rock will hit the bottom first
С
Both will hit at the same time
D
More information is needed
Answer:
C. Both will hit at the same time.
Explanation:
Gravity accelerates them both the same since the vacume has no other particles. Gravity pulls down at about 9.81 m/s/s on earth and since there are no air particles in a vacume, there is no air-resistance. Your final velocity can be found with the equation [tex]Vf=Vi+g*t[/tex]
Vf is final velocity and Vi is initial velocity. Them both accelerating at the same time with the same gravity means that the initial velocity will be the same for both and therfore so will the final velocity. All of that leads to them landing at the same time. This is all an assumption that they are being dropped from the same height.
Please correct me if I was wrong about anything said above.
Thanks!
If rock and a feather are dropped in a 98-meter-long tube in which there is a vacuum, Both will hit at the same time.
Why do objects fall at the same rate in a vacuum?If your heavy and light objects are in a vacuum, then they fall at the same speed. This is because they only have one force acting on them: gravity.
Which would fall with greater acceleration in a vacuum a leaf or a stone?Q. Which would fall with greater acceleration in a vacuum—a leaf or a stone. They would accelerate at the same rate.
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According to some nineteenth-century geo-
logical theories (now largely discredited), the
Earth has been shrinking as it gradually cools.
If so, how would g have changed over geo-
logical time?
1. It would increase; g is inversely proportional to the square of the radius of the Earth
2. It would decrease; the Earth’s radius is decreasing
3. It would not change; the mass of the Earth remained the same.
I really need this answer NOW. i’m taking a timed test. Will mark brainliest answer.
Answer:
What was it
Explanation:
It would increase; g is inversely proportional to the square of the radius of the Earth. The correct option is A.
What is geological theory?A current idea in geology that describes how the earth's crust is made up of a few big, hard plates that move independently of one another, causing deformation, volcanism, and seismic activity along their boundaries.
Because it explains how mountain ranges, earthquakes, volcanoes, shorelines, and other features often emerge where the moving plates contact along their boundaries, plate tectonics provides "the overall picture" of geology.
The Earth has been shrinking as it gradually cools, according to some geological hypotheses from the nineteenth century that have now been completely debunked.
If that were the case, it would rise since g is inversely proportional to the square of the Earth's radius.
Thus, the correct option is A.
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Solving steps and answer!
Answer:
162 cm
Explanation:
We are told that the Body surface are of a patient is given by the formula;
BSA = (√wh)/60
Where;
w is weight in kg
h is height in cm
We ware now given that;
w = 50 kg
BSA = 1.5
Thus;
1.5 = (√50h)/60
Multiply both sides by 60 to get;
90 = (√50h)
Square both sides to get;
90² = 50h
h = 90²/50
h = 162 cm
A DC motor connected to a switch-mode dc-dc converter goes into regenerative braking mode. The average current being supplied by the dc motor is 20 A. In the equivalent circuit of the dc motor, Ea=103 V, Ra=0.19 Ohms, and La=4 mH. Calculate the average power flow into the converter. Round answer to the nearest whole number.
Answer:
The correct answer is "2524 W".
Explanation:
The given values are:
Ia = 20 A
Ea = 103 V
Ra = 0.19 Ω
La = 4 mH
According to KVL,
⇒ [tex]V_0=E_a-I_aR_a[/tex]
On substituting the given values in the above equation, we get
⇒ [tex]=103-(20)(0.19)[/tex]
⇒ [tex]=103-3.8[/tex]
⇒ [tex]=126.2 \ V[/tex]
Now,[tex]=126.2\times 20[/tex]
The average power flow into the converter will be:
⇒ [tex]P=V_0 I_a[/tex]
On substituting the given values, we get
⇒ [tex]=(126.2\times 20)[/tex]
⇒ [tex]=2524 \ W[/tex]
Identify and sketch all the external forces acting on the chair. Because the chair can be represented as a point particle of mass m, draw the forces with their tails centered on the black dot in the middle of the chair. Be certain to draw your forces so that they have the correct orientation. Draw the vectors starting at the black dot. The location and orientation of the vectors will be graded. The length of the vectors will not be graded.
Answer:
y axis normal (N) and the weight (W)
x axis pplied force (F) and friction force (fr)
Explanation:
If we have a chair on a horizontal surface, the normal (N) and the weight (W) of the body act on the vertical axis.
On the x axis, the applied force (F) acts in the direction of movement and the friction force (fr) in the opposite direction of movement.
In this exercise we assume that the body tends to move to the right, all the forces can be seen in the adjoint
Analyze the data to identify the mathematical relationship between the
amplitude and energy of a mechanical wave. If mechanical wave A has an
amplitude of 4 cm and mechanical wave B has an amplitude of 5 cm, what
will be the relationship between the energy carried by the two waves?
Amplitude
Energy
A. Wave A has about 1.25 times more energy than wave B.
ОО
B. Wave A has about 1.6 times more energy twan wave B.
C. Wave B has about 1.6 times more energy than wave A.
O D. Wave A has about 1.15 times more energy than wave B.
Answer:
Its C
Explanation:
Because I got it wrong for you
Wave B has about 1.6 times more energy than wave A.
What is energy?
Energy is the ability or capability to do tasks, such as the ability to move an item (of a certain mass) by exerting force. Energy can exist in many different forms, including electrical, mechanical, chemical, thermal, or nuclear, and it can change its form.
The amplitude and energy of a mechanical wave. If mechanical wave A has an amplitude of 4 cm and mechanical wave B has an amplitude of 5 cm wave B has about 1.6 times more energy than wave A.
Wave B has about 1.6 times more energy than wave A.
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Can someone please help me with this worksheet. It’s due today and I have no idea what to do.
HELP ASAP PLS
A balloon with a positive charge will stick to a wall that has a negative charge.
What force causes this?
A. Gravity
B. Electric force
C. Magnetic force
D. Air gesistance
two students sit on a see-saw. archie is a hulking football player with a mass of 120 kg. clementine is a dainty cheerleader with a mass of 40 kg. the see-saw is 3.5 m in total length with the fulcrum at the center. if clementine sits at the end on one side, where must archie sit relative to the center to keep the see-saw balanced
Answer:
Archie must sit 0.58 m relative to the center to keep the see-saw balanced
Explanation:
Given the data in the question;
Mass of Archie [tex]m_{a}[/tex] = 120 kg
Mass of clementine [tex]m_{c}[/tex] = 40 kg
total length of see-saw L = 3.5 m
as illustrated on the image below, Fulcrum is at the center,
suppose Archie sits at a distance x from center then for balancing, we will have;
[tex]m_{a}[/tex] × x = [tex]m_{c}[/tex] × ( one end = 3.5/2 = 1.75)
so we substitute
120kg × x = 40kg × 1.75m
x12okg = 70 kg.m
x = 70 kg.m / 120 kg
x = 0.58 m
Therefore, Archie must sit 0.58 m relative to the center to keep the see-saw balanced
What is the speed of a train if it covers 69 km in 45
minutes.
Answer:
1.4km/h
Explanation:
distance/time = speed
69/45=1.4km/h
) A 73-mH solenoid inductor is wound on a form that is 0.80 m long and 0.10 m in diameter. A coil having a resistance of is tightly wound around the solenoid at its center. The mutual inductance of the coil and solenoid is At a given instant, the current in the solenoid is and is decreasing at the rate of At the given instant, what is the induced current in the coil
Complete question is;. A 73mH solenoid inductor is wound on a form that is 0.80m long and 0.10m in diameter a coil having a resistance of 7.7 ohms is tightly wound around the solenoid at its center the mutual inductance of the coil and solenoid is 19μH at a given instant the current in the solenoid is 820mA and is decreasing at the rate of 2.5A/s at the given instant what is the induced current in the coil
Answer:
6.169 μA
Explanation:
Formula for induced EMF is given by the equation;
EMF = M(di/dt). We are given;
di/dt = 2.5 A/s
M = 19μH = 19 × 10^(-6) H
Thus;
EMF = 19 × 10^(-6) × 2.5.
EMF = 47.5 × 10^(-6) V
Formula for current is;
i = EMF/R. R is resistance given as 7.7 ohms.
Thus; i = 47.5 × 10^(-6)/7.7
i = 6.169 μA
What term is used to describe DNA Replication?
Conservative
Un-conservative
Non-conservative
Semi-conservative
Answer:
Semi-conservative
Explanation:
Each strand of the original DNA molecule serves as a template for the production of its counterpart
A weightlifter holds a 1,500 N barbell 1 meter above the ground. One end of a 2-meter-long chain hangs from the center of the barbell. The chain has a total weight of 400 N. How much work (in J) is required to lift the barbell to a height of 2 m
Answer:
1800 J
Explanation:
We are given that
Weightlifter hold weight, w=1500N
Height of weightlifter from ground,h=1m
Length of chain=2m
Total weight of chain, w'=400 N
We have to find the work done required to lift the barbell to height of 2m.
Total work done=Work done to lift a barbell and half of the chain+ work done to lift the upper half of the chain
Total work done=[tex]1500+\frac{1}{2}(400)+\frac{1}{2}(400)(\frac{1}{2}(1))[/tex]
Total work done=[tex]1700+100[/tex]
Total work done=1800 J
Hence, work done is required to lift the barbell to a height of 2 m=1800 J
Determine one way you can contribute to water in the atmosphere in your day-to-day activities pleaseeeee helppp
Answer:
agricultural production of food
Explanation:
3. If the gravitational force between 2 objects is 50 N, what is the gravitational
force when the distance between the two is increased to four times the distance?
The gravitational force : 3.125 N
Further explanationGiven
F₁ = 50 N
Required
F₂
Solution
Newton's Gravity Law:
[tex]\rm F=G.\dfrac{m_1.m_2}{r^2}[/tex]
with F = gravitational force,
G = gravitational constant,
m1, m2 = mass of object,
r = distance between two objects.
The value of m and G are the same , so :
F₁ ≈ 1/r₁²
The distance between the two is increased to four times:
r₂ = 4r₁
F₂ = 1/(4r₁)²
F₂ = 1/16r₁²
F₂ = F₁ x 1/16
F₂ = 50 : 16
F₂ = 3.125 N
Explain why your PE and KE are usually not both high at the same time (If PE is high then usually KE is low)
Answer:
An object can have both kinetic and potential energy at the same time. ... As an object falls its potential energy decreases, while its kinetic energy increases. The decrease in potential energy is exactly equal to the increase in kinetic energy. Another important concept is work.
Explanation:
Answer:
KE:
energy which a body possesses by virtue of being in motion.
PE:
the energy possessed by a body by virtue of its position relative to others, stresses within itself, electric charge, and other factors.
Explanation:
Your welcome
Light-rail passenger trains that provide transportation within and between cities speed up and slow down with a nearly constant (and quite modest) acceleration. A train travels through a congested part of town at 4.0 m/s . Once free of this area, it speeds up to 11 m/s in 8.0 s. At the edge of town, the driver again accelerates, with the same acceleration, for another 16 s to reach a higher cruising speed. Part A What is the final speed
Answer:
25 m/s
Explanation:
Given that:
Initial speed, u = 4 m/s
Final velocity, V = 11 m/s
Time, t = 8 seconds
t2, = 16 seconds
Acceleration, a= (change in velocity) / time interval
a = (11 - 4) / 8
a = 7 / 8 = 0.875m/s²
Final velocity, v2 ;
Acceleration * t2
0.875 * 16 = 14
V2 = 14 m/s
Final speed : v + v2 = (11 + 14)m/s = 25m/s
Which option tells the forces that influence the movement of earths plates
Answer:
Gravity
Explanation:
You are concerned about the moon roof on your new sports car. It seems to flex when driving at high speeds. Calculate how much net force the moon roof must withstand and in what direction. Assume the moon roof is flat with an area of 0.5 m^2 and the pressure and velocity over the moon roof is constant. Your driving speed is 20 m/s, and the velocity over the moon roof is 30 m/s. The pressure inside the car is 90,500 N/m^2 and the freestream pressure and density in front of the car are 90,000 N/m^2 and 1.1 kg/m^3.
Answer:
Explanation:
We shall apply Bernoulli's formula to solve the problem . It is as follows .
P + ρ gh + 1/2 ρ v² = constant .
P₁ + ρ gh + 1/2 ρ v₁² = P₂ + ρ gh + 1/2 ρ v₂²
P₁ + 1/2 ρ v₁² = P₂ + 1/2 ρ v₂²
P₁ - P₂ = 1/2 ρ (v₂² - v₁² )
= .5 x 1,1 ( 30² - 20² )
= 275 N / m²
velocity over moon roof is high , pressure will be lower there by 275 N / m²
Given pressure difference already existing = 90500 - 90000 = 500 N / m²
Additional pressure difference due to velocity difference = 275 N / m²
Total pressure difference = 275 + 500 = 775 N / m²
Area of roof = .5 m²
Total force acting upwards on the roof
= .5 x 775 N
= 387.5 N .
A 97.1 kg horizontal circular platform rotates freely with no friction about its center at an initial angular velocity of 1.63 rad/s . A monkey drops a 8.97 kg bunch of bananas vertically onto the platform. They hit the platform at 45 of its radius from the center, adhere to it there, and continue to rotate with it. Then the monkey, with a mass of 22.1 kg , drops vertically to the edge of the platform, grasps it, and continues to rotate with the platform. Find the angular velocity of the platform with its load. Model the platform as a disk of radius 1.73 m .
Answer:
the final angular velocity of the platform with its load is 1.0356 rad/s
Explanation:
Given that;
mass of circular platform m = 97.1 kg
Initial angular velocity of platform ω₀ = 1.63 rad/s
mass of banana [tex]m_{b}[/tex] = 8.97 kg
at distance r = 4/5 { radius of platform }
mass of monkey [tex]m_{m}[/tex] = 22.1 kg
at edge = R
R = 1.73 m
now since there is No external Torque
Angular momentum will be conserved, so;
mR²/2 × ω₀ = [ mR²/2 + [tex]m_{b}[/tex] ([tex]\frac{4}{5}[/tex] R)² + [tex]m_{m}[/tex]R² ]w
m/2 × ω₀ = [ m/2 + [tex]m_{b}[/tex] ([tex]\frac{4}{5}[/tex] )² + [tex]m_{m}[/tex] ]w
we substitute
w = 97.1/2 × 1.63 / ( 97.1/2 + 8.97(16/25) + 22.1
w = 48.55 × [ 1.63 / ( 48.55 + 5.7408 + 22.1 )
w = 48.55 × [ 1.63 / ( 76.3908 ) ]
w = 48.55 × 0.02133
w = 1.0356 rad/s
Therefore; the final angular velocity of the platform with its load is 1.0356 rad/s
Two ropes are connected to a 200 kg dinghy. Two cousins each take one rope and pull. When the cousins pull in the same direction, the dinghy accelerates at a rate of 1.31 m/s2 to the east. If they pull in opposite directions, the dinghy has an acceleration of 0.526 m/s2 to the west. Assume the ropes are horizontal, and ignore any other horizontal forces acting on the dinghy. What is the magnitude of the force each cousin exerts on the dinghy
Answer:
The magnitude of the force each cousin exerts on the dinghy is 183.6 N and 78.4 N.
Explanation:
When the cousins pull in the same direction we have:
[tex] F_{1} + F_{2} = ma_{e} [/tex] (1)
Where:
F₁ and F₂ are the forces exerted by the two boys.
m: is the mass of the dinghy = 200 kg
[tex]a_{e}[/tex]: is the acceleration in the east direction
When the cousins pull in opposite directions we have:
[tex] F_{1} - F_{2} = ma_{w} [/tex] (2)
By adding equation (1) and (2):
[tex] 2F_{1} = m(a_{e} + a_{w}) [/tex]
[tex] F_{1} = \frac{200 kg(1.31 m/s^{2} + 0.526 m/s^{2})}{2} = 183.6 N [/tex]
Now, by entering F₁ into equation (1) we can find F₂:
[tex] F_{2} = ma_{e} - F_{1} = 200kg*1.31 m/s^{2} - 183.6 N = 78.4 N [/tex]
Therefore, the magnitude of the force each cousin exerts on the dinghy is 183.6 N and 78.4 N.
I hope it helps you!
A 3" diameter germanium wafer that is 0.020" thick at 300K has 1.015 x 10^17 As atoms added to it. What is the resistivity of the wafer? Germanium has 4.42 x10^22 atoms/cc, electron and hole mobilities are 3900 and 1900 cm^2/(V*s). What is the resistivity of the Ge in ohm*microns?
Answer:
0.546 ohm / μm
Explanation:
Given that :
N = 1.015 * 10^17
Electron mobility, u = 3900
Hole mobility, h = 1900
Ng = 4.42 x10^22
q = 1.6*10^-19
Resistivity = 1/qNu
Resistivsity (R) = 1/(1.6*10^-19 * 1.015 * 10^17 * 3900)
= 0.01578880889 ohm /cm
Resistivity of germanium :
R = 1 / 2q * sqrt(Ng) * sqrt(u*h)
R = 1 / 2 * 1.6*10^-19 * sqrt(4.42 x10^22) * sqrt(3900*1900)
R = 1 /0.0001831
R = 5461.4964 ohm /cm
5461.4964 / 10000
0.546 ohm / μm
If the coefficient of kinetic friction is 0.43 for a box sliding across your lab table and the
box weighs 7.4 N, what is the force of kinetic friction?
Answer:
3.2N
Explanation:
Given parameters:
Coefficient of kinetic friction = 0.43
Weight of box = 7.4N
Unknown:
Force of kinetic friction = ?
Solution:
The force of kinetic friction is given as:
Force of kinetic friction = UN
U is the coefficient of friction
N is the weight
Force of kinetic friction = 0.43 x 7.4 = 3.2N