Answer:
B
Explanation:
PLEASE HELP ASAP!
A machine has an efficiency of 70%. What happens to the other 30% of the work?
Answer:
The other 30% is lost from friction.
Explanation:
friction 30% ---> |O| <------ 70% work
A machine has an efficiency of 70%, and the remaining 30% of the input work is lost as waste energy or dissipated in the form of heat, noise, or vibration, which cannot be harnessed to do any useful work.
What is work done by machine?In any machine, the total work input is equal to the total work output plus any work that is lost or dissipated due to various factors such as friction, heat transfer, etc., so, for example, if a machine receives 100 units of energy as input, only 70 units of energy are converted into useful output work, and the remaining 30 units of energy are lost as waste energy.
Hence, the remaining 30% of the input work is lost as waste energy or dissipated in the form of heat, noise, or vibration, which cannot be harnessed to do any useful work.
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A 67.0 kg person is riding in a car moving at 19.0 m/s when the car runs into a bridge abutment. (Assume the initial velocity is in the positive direction.) (a) Calculate the average force (in N) on the person if he is stopped by a padded dashboard that compresses an average of 1.00 cm. (Indicate the direction with the sign of your answer.) N (b) Calculate the average force (in N) on the person if he is stopped by an air bag that compresses an average of 15.0 cm. (Indicate the direction with the sign of your answer.) N
Answer:
a) F = - 1.21 10⁶ N, b) F = - 8.06 10⁴ N
Explanation:
a) For this part let's use the kinematics relations
v² = v₀² - 2 a x
distance traveled to stop is x = 1.00 cm = 0.0100 cm, final speed is zero
0 = v₀² - 2 ax
a = v₀² / 2x
a = [tex]\frac{19^2 }{2 \ 0.01}[/tex]
a = 1.81 10⁴ m / s²
this acceleration is in the opposite direction to velocity
let's use Newton's second law
F = ma
F = 67.0 (-1.81 10⁴)
F = - 1.21 10⁶ N
the negative sign indicates that it is going in the opposite direction to the speed
b) in this case it is stopped by an airbag x = 15.0 cm = 0.15 m
a = v₀² / 2x
a = [tex]\frac{19^2}{2 \ 0.15}[/tex]
a = 1.203 10³ m / s²
calculate the force
F = m a
F = 67.0 (- 1.203 10³)
F = - 8.06 10⁴ N
PLEASE HELP ASAP
Jane told jill that the name sunflower comes from the fact that sunflowers follow the sun in the sky through out the day. jane said that sunflowers actually turn around on their stems to find the sun. to test this idea, jane and jill designed an experiment. they grew a pot of sunflowers outside in natural sunlight, one pot in the house near, but not directly in front of a window, and the final pot inside the house, away from all windows. the girls charted the direction of the sunflower heads throughout the day. all other growing conditions were the same: soil, water, pot size. the girls could not regulate the outdoor temperature, but since it was spring, the day and night temperatures were pretty close to the indoor temperature. which is an appropriate hypothesis for this experiment?
a) sunflowers will only grow in natural light.
b) sunflowers grown indoors will bend toward a source of natural light.
c) sunflower heads turn to follow the location of the sun, both indoors and out.
d) sunflowers grown away from natural light will not be as tall as sunflowers grown outdoors.
Set three resistances to 2, 3, and 5 Ohms in series, and determine the current in the circuit with an ammeter. Take the snapshot of the screen showing the circuits and the reading of the ammeter. Then, replace these three resistors with just one resistance of 10 Ohm. Determine the current running in the circuit. Take a snapshot showing the circuits and the reading of the ammeter. Is the current the same as in the previous experiment with the three resistors
Answer:
the current in the circuit must be the same.
Explanation:
The equivalent resistance in a series circuit is the sum of the resistances
in this case
R_{eq} = R₁ + R₂ + R₃
we calculate
R_{eq} = 2 + 3 + 5
R_{eq} = 10 Ω
We can see that the equivalent resistance is equal to the resistance to be changed, so the current in the circuit must be the same.
The only change there may be is due to the tolerances of the resistors
The image below represents water's... *
Answer:
it represents the physical changes.
Explanation:
I
What will the answers for a ,b and c be
Answer:
A. 1.6 Hz
B. 1000 m/s²
C. 50000 N
Explanation:
A. Determination of the frequency.
Period (T) = 0.625 s
Frequency (f) =?
f = 1/T
f = 1/0.625
f = 1.6 Hz
B. Determination of the acceleration.
Radius (r) = 10 m
Velocity (v) = 100 m/s
Acceleration (a) =?
a = v²/r
a = 100² / 10
a = 10000 / 10
a = 1000 m/s²
C. Determination of the net force.
Mass (m) = 50 Kg
Acceleration (a) = 1000 m/s²
Net force (F) =?
F = ma
F = 50 × 1000
F = 50000 N
. A box is pushed across the floor for a distance of 5 meters with a force of 50 Newtons in 5 seconds.
a. How much work is done?
b. What is the power?
Answer:The total amount of work is
W = F × s (force x distance)
Explanation: Explanation:
W
=
50
N
×
5
m
=
250
N
m
=
250
J
Done in 5 seconds the power is
p
=
W
t
where
t
=time
p
=
250
J
5
s
=
50
J
/
s
=
50
W
The work done in pushing the box is 250J b. The power is 50W.
What is Work done?When a force is applied to a body and the body undergoes a displacement we say that work is done. So, mathematically we can write work done as product of force and displacement. Its unit is joule(J).
W = F x D
where, F = force, D = Displacement
What is power?Power is the rate of doing work . If work is done by an appliance or object in less time then we can say that it has more power .Its unit is watt(W). Power is expressed as ,
P = W / t
where, W = work done ,t = time taken
To calculate the work done we use the formula
W = F X D
Given here, F = 50N displacement =5m
So, work done = 50 x 5 = 250J
Hence the work done in pushing a box across the floor for a distance of 5 meters with a force of 50 Newtons in 5 seconds is 250J.b. The power is given by ,P = W /t here, work done W = 250Jtime taken t = 5s
So, power is P = 250/5 =50W
Hence the solution of the question is
a. The work done in pushing the box is 250J
b. The power is 50W
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Does gravity increase or decrease with greater distance?
2) __________ are chemical messengers produced by the endocrine system and released into the bloodstream.
BRAINLIEST!
NO FILE HOSTING LINKS!!!
Answer:
Hormones
Explanation:
The glands that make up the endocrine system produce chemical messengers called hormones that travel through the blood to other parts of the body. Important endocrine glands include the pituitary, thyroid, parathyroid, thymus, and adrenal glands
The electric field at the center of a ring of charge is zero. At very large distances from the center of the ring along the ring's axis the electric field goes to zero. Find the distance from the center of the ring along the axis (perpendicular to the plane containing the ring) at which the magnitude of the electric field is a maximum. The radius of the ring is 7.55 cm and the total charge on the ring is 7.06E-6 C.
Answer:b[tex]4.29\times 10^6\ N/C[/tex]
Explanation:
Given
The radius of the ring is [tex]a=7.55\ cm[/tex]
The charge on the ring is [tex]Q=7.06\times 10^{-6}\ C[/tex]
Electric field along the axis at a distance [tex]x[/tex] is given by
[tex]E=\dfrac{kxQ}{(x^2+a^2)^{\frac{3}{2}}}[/tex]
To get the maximum value, differentiate [tex]E[/tex] w.r.t [tex]x[/tex] we get
[tex]E_{max}=\dfrac{2kQ}{3\sqrt{3}a^2}\quad [\text{at}\ x=\dfrac{a}{\sqrt{2}}]\\\\E_{max}=\dfrac{2\times 9\times 10^9\times 7.06\times 10^{-6}}{3\sqrt{3}(7.55\times 10^{-2})^2}\\\\E_{max}=\dfrac{24.456\times 10^3}{57\times 10^{-4}}=4.29\times 10^6\ N/C[/tex]
Does time stop in a black hole
Answer:
In standard GR, nothing exists at the center of a black hole. The center of a black hole is a singularity, and because GR fails at that point it is simply removed from the manifold. That means that the singularity is not part of spacetime.
To answer your question more realistically, we believe that GR is an approximate theory that fails well before you reach the center. Unfortunately, we have no good alternative theory with which to answer the question in the region where GR fails. We simply don’t have any data from that regime and it is very hard to formulate a good theory without data. So there very well could be time at the center, but we simply don’t have a good way to even guess.
Answer:
Black hole is a region of space having a gravitational field so intense that no matter or radiation can escape
Actually time can't be stop.
although black hole slower a time
Explanation:
Time never cannot be stop totally.
Find the Net Force on a truck with a mass of 1,500kg and an acceleration
of 10m/s2?
Answer:
15,000 N
Explanation:
F = ma = (1,500 kg)(10 m/s^2) = 15,000 N
List 4 significant problems with nuclear power plants.
Answer:
1. could result in widespread contamination of air and water.
2. creation of radioactive wastes such as uranium mill tailings, spent (used) reactor fuel, and other radioactive wastes.
3. nuclear meltdowns
4. mining lung cancer risk
#1 - Saturn has a mass of 5.683 x 10^26 kg. One of its moons, Titan, has a
mass of 1.345x10^23 kg. The center of Saturn to the center of Titan is 1.222
x 10^6 m. What is the magnitude of the gravitational force that attracts
Saturn and Titan? Please show work and formula
Answer:
F = G M1 M2 / R^2 attractive force
F = 6.67 * 10E-11 * 5.683 * 10E26 * 1.345 * 10E23 / (1.222 * 106)^2 N
F = 6.67 * 5.683 * 1.345 / 1.493 * 10E26 N = 3.414 * 10E27 N
what is the relationship between the perimeter and the side length of anequilateral triangle ?
Answer:
The length of the equilateral triangle's side is the length of the hypotenuse of the 30-60-90. Using this ratio, we find that the length of this triangle's hypotenuse is 4. Thus the perimeter of the equilateral triangle will be 4 multiplied by 3, which is 12.
1. You are given a bottle that contains 4.59 cm of a metallic solid. The total mass of the bottle
is 35.66 g. The empty bottle weighs 14.23 g. What is the density of the solid?
12. Which of these devices uses an electromagnet? O a light bulb O an electric motor O a refrigerator magnet a compass
Answer:
the third one with the refrigerator
what is Ethyl butyrate used for
Answer:
Ethyl butyrate is used as an artificial flavoring resembling orange juice or pineapple in alcoholic beverages, as an ingredient of fragrance, and as a solvent and plasticizer for cellulose. It is also used in the production of polyvinyl butyral (PVB).
Explanation:
What should you do after obtaining a numerical answer when solving a problem?
g A projectile of mass 3 kg is launched horizontally from an initial height 3 m with an initial velocity 10 m/s. This velocity in the x direction is preserved when you ignore air resistance. The projectile still accelerates in the vertical y direction toward the ground, but this is exactly the energy lost from potential energy. Energy is conserved as long as you use the total mechanical energy equation. What is the final kinetic energy as the projectile just reaches the ground
Answer:
The kinetic energy at ground will be "238.2 J".
Explanation:
The given values are:
mass,
m = 3 kg
Initial height,
h = 3 m
Initial velocity,
v = 10 m/s
By using the conservation of energy at points A and B,
⇒ [tex]E_A=E_B[/tex]
⇒ [tex]mgh+\frac{1}{2}mv^2=k_B[/tex]
On substituting the values, we get
⇒ [tex]3\times 9.8\times 3+\frac{1}{2}\times 3\times (10)^2=k_B[/tex]
⇒ [tex]88.2+0.5\times 3\times 100=k_B[/tex]
⇒ [tex]88.2+150=k_B[/tex]
⇒ [tex]238.2 =k_B[/tex]
Question 6.Why does a ball dropped from a certain height not bounce back 1 point
to the same height it was dropped from? *
Answer:
Because the coefficient of restitution is less than 1.
This coefficient is 1 for a perfectly elastic collision.
Some of the energy of the fall is absorbed by the ball so the ball cannot return to its original height.
Also, you have the effects of air resistance and some energy absorption of the the reflecting surface.
The magnetic field due to a utility wire is 0.10 mT when you are at a distance of 10 meters from it. What current (in Amperes) flows through the wire?
Answer:
I = 5000 A
Explanation:
We will use Ampere's Law to calculate the current:
[tex]B = \frac{\mu I}{2\pi r}\\\\[/tex]
where,
B = Magnetic Field Strength = 0.1 mT = 1 x 10⁻⁴ T
μ = Permeability of Free Space = 4π x 10⁻⁷ N/A²
I = Current = ?
r = radius = 10 m
Therefore,
[tex]1\ x\ 10^{-4}\ T = \frac{(4\pi\ x\ 10^{-7}\ N/A^2)(I)}{2\pi(10\ m)}\\\\I = \frac{(1\ x\ 10^{-4}\ T)(2\pi (10\ m))}{4\pi\ x\ 10^{-7}\ N/A^2}[/tex]
I = 5000 A
A bicycle pump contains 200 cm3 of air and is connected to a bicycle tyre. The volume of the tyre is 800 cm3. The pressure of the air in the tyre (it is ‘flat’) is 1.0 atmosphere, the same as the air in the pump. (= volume1). What is the total volume of the air initially?
Answer:
The total initial volume of air in the tire is 800 cm³
Explanation:
Given;
volume of air in the bicycle pump, V₁ = 200 cm³
volume of the tire, V₂ = 800 cm³
The total initial volume of air in the tire is 800 cm³ and when the pump is pushed in, the total volume of air in the tire becomes 200 cm³. This occurs because the new air pumped into the tire through the bicycle pump compresses the air that was previously in the tire and raises the pressure of the tire that was initially flat.
From Boyle's law, a decrease in volume causes an increase in pressure.
h. Briefly describe the process taking place in the image below and comment on the
function of the molecule at stage 1 and 3
(6)
pat
AHEMHFgjrhfrshfghesgrgregr
How efficient are the small and large scale solar-power systems used in individual homes and industrial settings? What is the environmental impact of the generation of solar power?
In detail plz
Answer:
[tex]\color{Blue}\huge\boxed{Answer} [/tex]
The potential environmental impacts associated with solar power—land use and habitat loss, water use, and the use of hazardous materials in manufacturing—can vary greatly depending on the technology, which includes two broad categories: photovoltaic (PV) solar cells or concentrating solar thermal plants (CSP).
Explanation:
I just answer the second question
A car travelling at 25 m/s has momentum 20,000 Kgm/s, calculate the mass of the car.
[tex] \Large {\underline { \sf {Required \; Solution :}}}[/tex]
We have ―
Velocity of the car, v = 25 m/sMomentum of the car, P = 20,000 kg.m/sWe have been asked to calculate the mass of the car, m.
[tex]\qquad\implies\boxed{\red{\sf{ P = mv}}}\\[/tex]
P denotes momentumm denotes massv denotes velocity[tex] \quad \twoheadrightarrow\sf { 20000 = 25m} \\ [/tex]
[tex] \quad \twoheadrightarrow\sf { \cancel{\dfrac{20000}{25}} = m} \\ [/tex]
[tex]\quad\twoheadrightarrow\boxed{\red{\sf{ m = 800 \; kg}}}\\[/tex]
Therefore, mass of the car is 800 kg.
What structure is represented by the letter C?
PLEASE HELP!!!!!!!!!!!!!
Choose 1 answer:
A) Lysosome
B) Nucleus
C) Vacuole
D) Mitochondria
Answer:
The picture is blacked out.
Answer:
If I'm correct the answer would be A) Lysosome.
The attachment is black so I can't promise you that it's the one you're looking for. But I did it on khan
Which of the following statements is true about the speed at which sound waves travel?
A:Sound travels faster through air
B:Sound travels faster in a vacuum
C:Sound travels faster through water
D:Sound travels faster through a solid
Answer: sound waves travel faster in solid than water or air.
In vacuum sound waves don't travel at all
Answer:
A: Sound travels faster through air
Explanation:
The speed of sound is the distance travelled per unit of time by a sound wave as it propagates through an elastic medium. At 20 °C, the speed of sound in air is about 343 metres per second, or a kilometre in 2.9 s or a mile in 4.7 s.
Which is a form of precipitation?
A. Runoff
B. Rain
C. Gas
D. Evaporation
Answer:
D. Evaporation
Explanation:
Just did it made 100%
A 30 kg child went down a 10 m tall slide. Assuming no energy was lost as friction, what was the child's velocity when he reached the
bottom?
I
