Answer:
the answer is 4
Explanation:
just answer the question
An ideal heat engine absorbs 97.2 kJ of heat and exhausts 83.8 kJ of heat in each cycle. What is the efficiency of the engine?
Answer:
13.7%
Explanation:
Given that,
Heat absorbed by the engine = 97.2 kJ
Heat exhausted by the engine in each cycle = 83.8 kJ
We need to find the efficiency of the engine. It is calculated by the formula.
[tex]\eta=1-\dfrac{Q_e}{Q_a}\\\\=1-\dfrac{83.8}{97.2}\\\\=0.137\\\\=13.7\%[/tex]
so, the efficiency of heat engine is 13.7%.
An athlete stretches a spring an extra 40.0 cm beyond its initial length. How much energy has he transferred to the spring, if the spring constant is 52.9 N/cm?
a) 4230 kJ
b) 4230 J
c) 423 kJ
d) 423 J
Answer:
b) 4230 JExplanation:
Step one:
given data
extension= 40cm
Spring constant K= 52.9N/cm
Step two:
Required
the Kinetic Energy KE
the expression to find the kinetic energy is
KE= 1/2ke^2
substituting our data we have
KE= 1/2*52.9*40^2
KE=0.5*52.9*1600
KE= 42320Joules
The answer is b) 4230 J
A disk between vertebrae in the spine is subjected to a shearing force of 600 N. Find its shear deformation, taking it to have the shear modulus of 1 x 109 N/m2. The disk is equivalent to a solid cylinder 0.700 cm high and 4.00 cm in diameter.
Answer:
3.34×10^-6m
Explanation:
The shear modulus can also be regarded as the rigidity. It is the ratio of shear stress and shear strain
can be expressed as
shear stress/(shear strain)
= (F/A)/(Lo/ . Δx)
Stress=Force/Area
The sheear stress can be expressed below as
F Lo /(A *Δx)
Where A=area of the disk= πd^2/4
F=shearing force force= 600N
Δx= distance
S= shear modulus= 1 x 109 N/m2
Lo= Lenght of the cylinder= 0.700 cm=7×10^-2m
If we make Δx subject of the formula we have
Δx= FLo/(SA)
If we substitute the Area A we have
Δx= FLo/[S(πd^2/4]
Δx=4FLo/(πd^2 *S)
If we input the values we have
(4×600×0.7×10^-2)/10^9 × 3.14 ×(4×10^-2)^2
= 3.35×10^-6m
Therefore, its shear deformation is 3.35×10^-6m
A=area of the disk= πd^2/4
= [3.142×(4×10^-2)^2]/4
Jadeen says that you can increase the resistance of a copper wire by hammering the wire to make it narrower and longer. Arnell says that you can increase its resistance by heating the wire. Which one, if either, is correct, and why?
1) Arnell, because the conductivity of the wire increases when it is heated.
2) Arnell, because the conductivity of the wire decreases when it is heated.
3) Jadeen, because the conductivity of a wire is directly proportional to its area and inversely proportional to its length.
4) Jadeen, because the conductivity of a copper wire does not increase and might decrease when it is hammered.
5) Both are correct because (b) and (d) are both correct.
Answer:
The answer is "Option 5".
Explanation:
Jadeen claims that only by hitting the wire to make it thinner and wider, it can improve a copper wire's strength, which is why a copper wire's permeability doesn't quite improve and can reduce once it is pounded. Arnell says so by heating its wire, it can improve its strength, and when it is heated, the wire's permeability reduces.
The change in motion (acceleration) of an object depends on
The size of the force
The mass of the object
BOTH the size of the force AND the mass of the object
Answer:
BOTH the size of the force AND the mass of the object
Explanation:
Acceleration of an object is the rate of change of its velocity.
The relation between force, mass and acceleration is given by the formula as follows :
F = ma
m is mass
a is acceleration
It would mean that the change in motion or the acceleration of an object depends on both the size of the force and the mass of the object. Hence, the correct option is (c).
You are throwing a ball straight up in the air. At the highest point, the ball's.....
acceleration is nonzero, but its velocity is zero.
velocity and acceleration are both nonzero.
velocity is nonzero but its acceleration is zero.
velocity and acceleration are zero.
Answer:
velocity and acceleration are zero.
When a ball is thrown exactly straight up in the air, at its highest point, velocity and acceleration are zero.
This is because, at the ball's highest point, the ball is not moving in any direction meaning the vector quantity (direction and magnitude) is zero for both velocity and acceleration.
which energy resource is renewable
Explanation:
solar energy is the answer
Light travels from a
laser across an 8 m
room where it reflects
off a mirror. Uniform or non uniform velocity
Answer:
Non-uniform velocity as the laser light beam has got reflected by the mirror
And as the light got reflected there is a change in velocity making it non-uniform velocity
What is the answer to this question number 2?
Answer:
1⁺ ion
Explanation:
Metals in the first group on the periodic table will prefer to form 1⁺ ion. This is because the 1 valence electron in their orbital.
Most metals are electropositive and would prefer to lose electrons than to gain it.
Like all metals, the group 1 elements called the alkali metals would prefer to lose and electron.
On losing an electron the number of protons is then greater than the number of electrons. This leaves a net positive charge.
The practice of science can answer only scientific questions. And scientific
questions guide the design of investigations. What must be true of the possible answers to a scientific question?
A. They can be supported by evidence.
B. They agree with all prior experiments.
C. They are popular with a majority of scientists.
D. They lead to increased funding of scientific research.
Correct answer is A! Ap3x approved
Answer:
a
Explanation:
As the scientific questions guide the design of investigation, They must be supported by They can be supported by evidence.
The correct option is A.
what is the scientific investigation?Scientific investigation is the process of looking for answers by doing extensive research and finding the answers through experimental results.
The scientific investigation very much relies on true experimental results that can be supported by evidence.
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helppp please ?????????
Answer:
v=59[m/s]
Explanation:
To solve this problem we must use the principle of conservation of energy, which tells us that energy is transformed from Kinetic to potential or vice versa. At the moment when the car is at the top before falling down the cliff, we have the car moving at speed 50 [m/s] (kinetic energy) also it is 50 [m] above ground level (potential energy).
[tex]E_{k1}+E_{p1}=E_{k2}\\[/tex]
where:
Ek1 = kinetic energy before falling [J]
Ep1 = potential energy before falling [J]
Ek2 = kinetic energy in the ground [J]
The potential energy can be calculated by means of the following equation.
[tex]E_{p}=m*g*h[/tex]
where:
m = mass = 500 [kg]
g = gravity acceleration = 9.81 [m/s²]
h = elevation = 50 [m]
Whereas the kinetic energy can be calculated by means of the following equation.
[tex]E_{k}=\frac{1}{2}*m*v^{2}[/tex]
where:
v = velocity = 50 [m/s]
Now replacing in the general equation:
[tex]\frac{1}{2} *500*(50)^{2} +500*9.81*50=\frac{1}{2} *500*v^{2}\\625000+245250=250*v^{2} \\250*v^{2} =870250\\v=\sqrt{870250/250} \\v=59[m/s][/tex]
A car is moving in a straight line with the same speed of 100 m/s ,the acceleration in this
case is
a= 100 m/s2
a=10 m/s2
a=1000 m/s2
a= 0 m/s2
Answer:
a = 0m/s²
Explanation:
Average acceleration = (change in velocity)/(time it takes). Since the car's change in velocity is zero, its acceleration is zero.
What is the function of a switch in an electrical circuit?
A. It interrupts the low of electrons when it is open.
B. It resists the flow of electrons when it is open.
C. It interrupts the flow of electrons when it is closed.
D. It resists the flow of electrons when it is closed.
Correct answer is A!! Ap3x approved
Answer:
A. It interrupts the low of electrons when it is open.
Explanation:
The switch in an electrical circuit interrupts the flow of electrons when it is open. Therefore, option (A) is correct.
What is an electrical circuit?The electric circuits can be described as closed-loop or paths, forming a network of electrical components where electrons flow. The path is generally made using electrical wires. The start-off point from where the electrons start flowing is known as the source, whereas the point where electrons leave the electrical circuit is known as the return.
The switch can be described as a small gap in the circuit. There are many types of switches. A switch is used to open or close an electrical circuit. A switch can be described as an electrical component that can be used to turn on and turn off any equipment.
When the switch of an electrical circuit is off, the circuit is open, and there is no flow of current or electrons. The current flow when the circuit is closed, therefore the switch should be on.
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In order to prevent injury in a car crash, it is recommended that you _______.
A) Increase the time of the collision.
B) Increase the change in momentum of the collision.
C) Increase the force in the collision.
D) Increase the initial velocity of the collision.
Increase of momentum of the collision will have the car in a unsettling position, creating an unsettling spot for it. Moreover increasing this would most likely take worse effect, it is better than increasing the time, which will only create the car faster. Let me show you what I mean...
A) Creates the car go faster, creating an even worse tragedy. B) save this for later...C) Increasing force will only result in worse damage.And finally, D) Increasing the velocity is basically increasing speed, once again, making things worse.So overall in this piece, the answer may very well end up being B. I sincerely hope this helped you by whatever means possible. It's logic that helps in real life situations, so take this as a little lesson- I guess :3A circuit can only light up a lightbulb if there is a ______ path for electricity to travel from one end of the energy source to the other end.
Answer:
Continuous
Explanation:
A circuit can only light up a lightbulb if there is a continuous path for electricity to travel from one end of the energy source to the other end.
Answer:
continuios
Explanation:
A golf ball flies through the air after being struck with a golf club. Which of the following statements describes the force on the ball as momentum is transferred between the club and ball?
A. The ball does not experience any force.
B. The force experienced by the ball is greater than the force experienced by the club.
C. The force experienced by the ball equals the force experienced by the club.
D. The force experienced by the ball is weaker than the force experienced by the club.
Answer:
C) The force experienced by the ball equals the force experienced by the club.
Explanation:
When the golfer strikes the ball with his club, the club exerts a force on the ball. Due to Newton's Third Law Of Motion [Every Action has an equal and opposite reaction], the ball also exerts an equal force on the club. However,
As the mass of the club is usually greater than the mass of the ball, it accelerates slower; While the ball way faster, following the equation : F=ma
Students are using a mallet to hit a drum. The diagram below shows this action.
Drum
Drum
When the mallet
hits the drum,
the drum skin
begins to vibrate.
particles of air
compressed
together
particles of air
compressed
together
Mallet
particles of air
moving apart wave of
again
compressed
particles moving
outward
Which statement BEST describes the phenomenon illustrated in the model?
Sound waves are being transmitted through the air in the drum.
Sound waves are being transferred from the mallet to the drum.
O Sound waves are being absorbed by the drum.
Sound waves are being reflected by the drum.
Answer:
A
Explanation:
i think
At the top of Mt. Everest (8850 m) a climber and their equipment (80 kg) has how much
potential energy?
Determine the distance between a newly discovered planet and its single moon if the orbital period of the moon is 1.2 Earth days and the mass of the planet it orbits is 9.38E24 kg.You may assume the orbit to be circular.
Answer:
The distance is [tex]r = 55430496 \ m[/tex]
Explanation:
From the question we are told that
The period of the moon [tex]T = 1.2 days = 1.2 * 24 * 3600 = 103680 \ s[/tex]
The mass of the planet is [tex]m_p = 9.38*10^{24} kg[/tex]
Generally the period of the moon is mathematically represented as
[tex]T = 2 * \pi * \sqrt{ \frac{r^3 }{ G * m_p } }[/tex]
Here G is the gravitational constant with value
[tex]G = 6.67 *10^{-11} \ N \cdot m^2/kg^2[/tex]
=> [tex]T = 2 * \pi * \sqrt{ \frac{r^3 }{ G * m_p } }[/tex]
=> [tex]103680 = 2 * 3.142 * \sqrt{ \frac{r^3 }{ 6.67*10^{-11} * 9.38*10^{24} } }[/tex]
=> [tex]272218492.31 = \frac{r^3}{ 6.67 *10^{-11} * 9.38*10^{24}}[/tex]
=> [tex]r = \sqrt[3]{ 1.7031241*10^{23}}[/tex]j
=> [tex]r = 55430496 \ m[/tex]
The rise of a line on a distance-versus-time graph is 400 km and the run is 50 hours. What is the speed of the object represented by this graph? help 5 mins remaining
Answer:
400km/50h = 90m/s..
Explanation:
..
Given the distance covered and time elapsed, the speed of the object represented by the graph is 8km/hr.
What is Speed?Speed is simply referred to as distance traveled per unit time.
Mathematically, Speed = Distance ÷ time.
Given the data in the question;
Distance it must cover d = 400kmTime elapsed t = 50hrsSpeed S = ?Speed = Distance ÷ time
Speed = 400km ÷ 50hrs
Speed = 8km/hr
Given the distance covered and time elapsed, the speed of the object represented by the graph is 8km/hr
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Question 1 of 20
Which statement best describes the effect of the magnet on the block of
material next to it?
is N
O
A. The magnet has magnetized the center of the block.
U
B. The magnet has magnetized the right side of the block.
C. The magnet has magnetized the whole block.
ОО
D. The magnet has magnetized the left side of the block.
Answer:
B. The magnet has magnetized the right side of the block.
Explanation:
a pe x
1. The mass of the Earth is 81 times the mass of the Moon. Using Newton's Law of Gravity, what would the effect of gravitation be if the mass of the Moon were increased by four times and the distance between Earth and
the Moon were cut in half?
Answer:
effects of gravity on the Moon and Earth
Explanation: Newton found the Moon's inward acceleration in its orbit to be 0.0027 metre per second per second, the same as (1/60)2 of the acceleration of a falling object at the surface of Earth.
How long would it take a train traveling at 18 m/s to travel 7,500 m? Answer in minutes.
Please I need help !!
Answer:
6.94446 min
Explanation:
t=s/v
Which answer below defines three of the five methods of weather forecasting?
Storm Chasing/ Persistent Forecasting/ Long-Range Forecasting
Storm Chasing/ Short Term Forecasting/Medium Range
Forecasting Persistent Forecasting/ Now-casting/ Short Term Forecasting
Now-casting/ Observing cast/ Short Term Forecasting
Answer: Storm Chasing/ Persistent Forecasting/ Long-Range Forecasting
Explanation:
Storm chasing is identification of the severe weather condition for the purpose of scientific investigation.
Persistent forecasting can be defined as the standard of comparison of the weather forecasting skills.
Long range forecast can provide the expected the condition of the atmospheric and oceanic condition.
Answer:
Persistent Forecasting/ Now-casting/ Short Term Forecasting
Explanation:
i just took the test and got it right. Happy holidays. Hope i helped. Maybe i can get brainlist??:)
To suck lemonade of density 1000 kg/m3 up a straw to a maximum height of 3.47 cm, what minimum gauge pressure (in atmospheres) must you produce in your lungs?
Answer:
The minimum gauge pressure you must produce in your lung is -3.356 x 10⁻³ atm
Explanation:
Given;
density of the lemonade, ρ = 1000 kg/m³
maximum height of the lemonade, h₂ = 3.47 cm = 0.0347 m
The minimum gauge pressure you must produce in your lung is given by Bernoulli’s equation;
P₂ + ρgh₂ = P₁ + ρgh₁
P₂ = P₁ + ρgh₁ - ρgh₂
P₂ = P₁ + ρg(h₁ - h₂)
P₂ = P₁ + ρg(0 - h₂)
P₂ = P₁ - ρgh₂
P₂ = 0 - ρgh₂
P₂ = - ρgh₂
P₁ = -(1000)(9.8)(0.0347)
P = -340.06 N/m²
The gauge pressure (in atmospheres) is given as;
P = -340.06 / 101325
P = -0.003356 atm
P = -3.356 x 10⁻³ atm
Therefore, the minimum gauge pressure you must produce in your lung is -3.356 x 10⁻³ atm
7) While having an existential crisis you lay on the floor to stare at the ceiling. The normal force you experience from the ground is likely equal to...
A The parallel component of the your weight
B Your weight
C The friction between the you and the ground
D Your mass
Answer:
The correct answer is B. your weight
Explanation:
Newton's third law states that every action has an equal and opposite reaction. You may not think this, but when you're standing on the floor, you are exerting a force against the floor: your weight, caused by gravity, is pulling you down. The floor is reacting by pushing back: we call this force the reaction force. -Google
Answer:
kkk
Explanation:
Why does a Galilean telescope have narrower field of view than an Keplerian telescope with the same size lenses?
Answer:
This is due to the eye piece consisting of a diverging lens
Explanation:
Galilean telescope have a narrower field of view than an Keplerian telescope with the same size lenses due to the eye piece consisting of a diverging lens while the Keplerian telescope eye piece has a converging lens.
The presence of a converging lens in the Keplerian telescope enables it to have a larger angle difference while the Galilean telescope diverging lens enables it to have a smaller angle difference which explains its narrow field of view.
Suppose your mass is 72.5 kg and you climb 40 stairs of height 18 cm in 17.0 s. What is your power output as you climb the stairs?
Answer:
Your power output as you climb the stairs is 300.92 Watts.
Explanation:
Power is the amount of work per unit of time that some object or system produces. Power is calculated by:
[tex]P=\frac{W}{t}[/tex]
Power is measured in watts (W), equivalent to one joule (J) of work done per second (s).
Work is defined in physics as the force that is applied to a body to move it from one point to another. The work is calculated as the multiplication of the force by the distance:
Work = F*d
Newton's second law says that the acceleration of a body is proportional to the resultant of forces on the acting and inversely proportional to its mass. This is expressed by the equation:
F=m*a
In this case,
considering that the force of gravity acting on you, the force is:
F=m*a= 72.5 kg * 9.8 [tex]\frac{m}{s^{2} }[/tex] =710.5 N
The distance is the multiplication between the number of stairs and the height of the stairs in meters (18 cm= 0.18 m, being 100 cm= 1 m):
d = 40 * 0.18 m= 7.2 m
Then:
Work= 710.5 N* 7.2 m
Work= 5,115.6 J
So finally the power can be calculated as:
[tex]P=\frac{5,115.6 J}{17s}[/tex]
P= 300.92 Watts
Your power output as you climb the stairs is 300.92 Watts.
This diagram shows a baseball’s motion.
A baseball is shown at 5 positions along an arc from left to right. A is far left and C is center, with B halfway between A and C. E is far right with D halfway between C and E.
Which statement is best supported by the diagram?
Kinetic energy becomes potential energy between points R and S.
Maximum potential energy is at point P.
Maximum potential energy is at point R.
Potential energy becomes kinetic energy between points P and Q.
Answer:
c
Explanation:
Maximum potential energy is at point R is best supported by the diagram. Therefore, the correct option is option C among all the given options.
What is motion?In physics, motion is a function of a body's position or orientation over time. Translation is defined as movement across a line or even a curve. Rotation is a motion that modifies a body's orientation. In all scenarios, the acceleration and directed speed of every point on the body are equal (time rate of change of velocity).
Every movement has a frame of reference to which it is related. A body isn't in motion when it is said to be at rest; rather, it is being characterized in relation to a reference frame that's also moving with the body. Maximum potential energy is at point R is best supported by the diagram.
Therefore, the correct option is option C.
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The scientific term describing the ball changing position as it goes from
Steph Curry's hand, into the air, and through the hoop.
A= velocity
B= speed
C= vector
D= motion
Answer:
Vector
Explanation:
Vector is a quantity that shows the direction or path through which a body travels with as it changes position.
As body travels, the direction sometimes changes and this is described by the vector of the body.
Velocity is a vector quantity that describes the displacement per unit of time of a body.
Speed is a scalar that deals with the distance covered per time
So, a vector specifies the magnitude of a physical quantity and also the direction through which it travels.