Answer:
Since i dot i = 1 and j dot j = 1 and k dot k = 1 and the other terms are zero
(7 i - 3 j + 2 k) dot (4 i + 5 j - 3 k) = 28 - 15 -6 = 7
What was Bear B's average speed in m/min? (No units required for answer. Type your answer.)
Answer:
43
Explanation:
you divide 2600 by 60 and your answer is 43.3333333
I just took the quiz and got it right!
what are the 3 sub particles of an atom
Answer:
Subatomic particles include electrons, the negatively charged, almost massless particles that nevertheless account for most of the size of the atom, and they include the heavier building blocks of the small but very dense nucleus of the atom, the positively charged protons and the electrically neutral neutrons.
Answer:
Neutron, Proton and Electron
Explanation:
5. Two buses X and Y started moving in opposite directions
from a point. After 5 minute Xcovered distance of 250mm
and y covered the distance of 300m. Calculate the relative
velocity.
Answer:
v = 0.166 [mm/min]
Explanation:
To solve this problem we must calculate the speed of each bus by means of the following formula that relates the displacement with time.
V = displacement / time
displacement = 250 [mm]
time = 5[min] = 300 [s]
Vx = 250/300 = 0.833[mm/min]
Vy = 300/300 = 1 [mm/min]
The relative velocity is the subtraction of the velocities, since the velocities are in opposite directions.
v = (1 - 0.833) = 0.166 [mm/min]
Because mass is determined from protons
and neutrons, what conclusion can you
make?
Answer:
Electrons have virtually no mass
Explanation:
I had a test an this was the right answer^
Answer: Electrons have virtually no mass
Explanation: on edpuzzle that was the answer
What Health Related Component of Physical Fitness is the ability of the heart and lungs to supply oxygen to the body? a. Muscular Strength c. Cardiorespiratory Endurance b. Muscular Endurance d. Flexibility
Megan is eating a Snickers and decides not to finish the last it of it. She drops the snickers into a trashcan below. What happens to the speed of the piece of Snickers as it falls towards the trashcan?
Answer:
i like trains 45654
Explanation:
Newton's Law of Gravitation says that the magnitude F of the force exerted by a body of mass m on a body of mass M isF = GmMr2where G is the gravitational constant and r is the distance between the bodies.(a) Find dF/dr.dFdr = What is the meaning of dF/dr?dF/dr represents the rate of change of the distance between the bodies with respect to the force.dF/dr represents the rate of change of the mass with respect to the force. dF/dr represents the rate of change of the force with respect to the distance between the bodies.dF/dr represents the amount of force per distance.dF/dr represents the rate of change of the mass with respect to the distance between the bodies.What does the minus sign indicate?The minus sign indicates that the force between the bodies is decreasing.The minus sign indicates that the bodies are being forced in the negative direction. The minus sign indicates that as the distance between the bodies increases, the magnitude of the force decreases.The minus sign indicates that as the distance between the bodies decreases, the magnitude of the force remains constant.The minus sign indicates that as the distance between the bodies increases, the magnitude of the force increases.
Answer:
Explanation:
Which statement is supported by Kepler's laws?
O The closer a planet is to the Sun, the faster it moves.
O The farther a planet is from the Sun, the faster it moves.
O As a planet moves away from the Sun, its gravitational force increases.
O As a planet moves away from the Sun, its gravitational force remains the same.
Answer:
A. The closer a planet is to the Sun, the faster it moves.
Explanation:
According to this law, planets move around the sun in elliptical orbits. An imaginary lines drawn from the center of Sun to center of planets will sweep equal area in equal time interval.
Answer option B,C&D is incorrect because planets that are far away from the Sun take more time to move all around the Sun and experience less gravitational force and move slower than those near the Sun.
Answer:
a
i am never wrong
What indicates that an object has been subjected to an unbalanced force?
You may have noticed runaway truck lanes while driving in the mountains. These gravel-filled lanes are designed to stop trucks that have lost their brakes on mountain grades. Typically, such a lane is horizontal (if possible) and about 36.0 m36.0 m long. Think of the ground as exerting a frictional drag force on the truck. A truck enters a typical runaway lane with a speed of 50.5 mph50.5 mph ( 22.6 m/s22.6 m/s ). Use the work-energy theorem to find the minimum coefficient of kinetic friction between the truck and the lane to be able to stop the truck.
Answer:
The coefficient of kinetic friction [tex]\mu_k = 0.724[/tex]
Explanation:
From the question we are told that
The length of the lane is [tex]l = 36.0 \ m[/tex]
The speed of the truck is [tex]v = 22.6\ m/s[/tex]
Generally from the work-energy theorem we have that
[tex]\Delta KE = N * \mu_k * l[/tex]
Here N is the normal force acting on the truck which is mathematically represented as
[tex]\Delta KE[/tex] is the change in kinetic energy which is mathematically represented as
[tex]\Delta KE = \frac{1}{2} * m * v^2 [/tex]
=> [tex]\Delta KE = 0.5 * m * 22.6^2 [/tex]
=> [tex]\Delta KE = 255.38m [/tex]
[tex] 255.38m = m * 9.8 * \mu_k * 36.0 [/tex]
=> [tex] 255.38 = 352.8 * \mu_k [/tex]
=> [tex]\mu_k = 0.724[/tex]
Suppose an octopus knows an enemy is nearby. Which two things would the octopus most likely do to escape?
A. Hide in a small space
B. Find something to eat
C. Attract a mate
D. Change its color
E. Show happiness or sadness
Answer:
A and D
Explanation:
Oil is a powerful source of energy used for cars, machines, and many other purposes. While studying sources of energy that could replace the use of oil, a student thinks about solar power, wind power, nuclear power, and electric batteries. The students asks, "Which type of source will waste the least energy and provide the most energy in all situations?" Which best describes why a scientist would ask a different question than this one? The question asks about subjective personal preferences regarding energy. The question focuses on the objective measurements of amounts of energy. The question has too wide of a focus, as though all situations can be studied at once. The question is focused on the future and finding new answers about changing needs.
Answer:
The question has too wide of a focus, as though all situations can be studied at once.
Explanation:
Please help I don’t know how to do this
Answer:
2.2 m/sExplanation:
formula to be used is: a = ∆v/∆t
where:
a = 0.09 m/s²
∆t = 10 s
∆v = a*∆t
= (0.09 m/s²)(10 s)
= 0.9 m/s
Vivian's final speed:
= initial speed + change in speed
= 1.3 m/s + 0.9 m/s
= 2.2 m/s
Mars has two moons, Phobos and Deimos. Phobos orbits Mars at a distance of 9380 km from Mars's center, while Deimos orbits at 23,500 km
from the center.
What is the ratio of the orbital period of Deimos to that of Phobos?
Answer:
The ratio is [tex]\frac{T_1}{T_2} = 3.965 [/tex]
Explanation:
From the question we are told that
The radius of Phobos orbit is R_2 = 9380 km
The radius of Deimos orbit is [tex]R_1 = 23500 \ km[/tex]
Generally from Kepler's third law
[tex]T^2 = \frac{ 4 * \pi^2 * R^3}{G * M }[/tex]
Here M is the mass of Mars which is constant
G is the gravitational constant
So we see that [tex]\frac{ 4 * \pi^2 }{G * M } = constant[/tex]
[tex]T^2 = R^3 * constant [/tex]
=> [tex][\frac{T_1}{T_2} ]^2 = [\frac{R_1}{R_2} ]^3[/tex]
Here [tex]T_1[/tex] is the period of Deimos
and [tex]T_1[/tex] is the period of Phobos
So
[tex][\frac{T_1}{T_2} ] = [\frac{R_1}{R_2} ]^{\frac{3}{2}}[/tex]
=> [tex]\frac{T_1}{T_2} = [\frac{23500 }{9380} ]^{\frac{3}{2}}][/tex]
=> [tex]\frac{T_1}{T_2} = 3.965 [/tex]
The given values are:
Radius, r = 23500 kmDistance = 9380 kmWe know the formula,
→ [tex]v = \frac{2 \pi r}{T}[/tex]
then,
→ [tex]\sqrt{\frac{GM_{mars}}{r} } =\frac{2 \pi r}{T}[/tex]
or,
→ [tex]T = 2 \pi \sqrt{\frac{r^3}{GM_{mars}} }[/tex]
Now,
The orbital period of Deimos will be:
[tex]= 2 \pi \sqrt{\frac{(23500)^3}{GM_{mars}} }[/tex]
The orbital period of Phobos will be:
[tex]= 2 \pi \sqrt{\frac{(9380)^3}{GM_{mars}} }[/tex]
hence,
The ratio will be:
→ [tex]\frac{T_{deimos}}{T_{Phobos}}[/tex] = [tex]\frac{2 \pi \sqrt{\frac{(23500)^3}{GM_{mars}} } }{2 \pi \sqrt{\frac{(9380)^3}{GM_{mars}} }}[/tex]
= [tex]\sqrt{(\frac{23500}{9380})^3 }[/tex]
= [tex]3.96[/tex]
Thus the above answer is correct.
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To escape from a horrible fire, two people are forced to jump from the third story of a burning building onto solid concrete. Which person is more likely to sustain fewer injuries: the jumper who comes to an abrupt halt when he lands or the jumper who bounces after impact?
The jumper who bounces after impact is more likely to sustain fewer injuries since he/she has a lesser change in momentum.
Impulse:According to the question:
Two people are forced to jump from the third story of a burning building onto solid concrete to escape the fire.
One person lands on the ground and comes to an abrupt halt.
The other person bounces off the ground after impact.
We know that the sudden change in momentum results in impulse. Impulse is directly proportional to the force exerted on the body. The greater the impulse, the larger the force exerted on the body.
If we assume that both the person have the same mass then:
The person coming to an abrupt halt has a larger change in momentum that the person who bounces off. Since the person who bounces off continues to be in motion, retaining some of the momenta while the direction of motion changes.
So the person who bounces after impact will sustain fewer injuries.
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What causes different colors to appear in the sky.
Answer:
The colors of the sunset result from a phenomenon called scattering. Molecules and small particles in the atmosphere change the direction of light rays, causing them to scatter. ... The short-wavelength blue and violet are scattered by molecules in the air much more than other colors of the spectrum.
Explanation:
Answer:
The scattering and reflection of light by dust particles.
We can compare these two interactions on the basis of impulse (see above), but sometimes, we are more interested in the forces (human body can withstand very large amount of impulse, if it's delivered over a long time with small forces, but we cannot withstand very large forces lasting over more than a few milliseconds, delivering relatively small impulse). In order to estimate average force from impulse, we need the duration of interaction. Suppose that the contact of the bat with the baseball in (b) lasts for 0.7 milliseconds. What is the magnitude of the average force that the bat exerts on the baseball, for the duration of contact
Complete Question
The complete question is shown on the first uploaded image
Answer:
a
[tex]I = 476 \ N \cdot s [/tex]
b
[tex]I_1 = 14.21 \ N\cdot s [/tex]
c
[tex]F = 20300 \ N [/tex]
Explanation:
Considering the first question
From the question we are told that
The force produced is [tex]F = 3400 \ N[/tex]
The duration of the punch is [tex]t = 0.14 \ s[/tex]
Generally the impulse delivered is mathematically represented as
[tex]I = F * t[/tex]
=> [tex]I = 3400 * 0.14[/tex]
=> [tex]I = 476 \ N \cdot s [/tex]
Considering the second question
The approaching velocity of the ball is [tex]v_b = 45 \ m/s[/tex]
The leaving velocity of the ball is [tex]v_l = -53 \ m/s[/tex]
The mass of the ball is [tex]m_b = 0.145 \ kg[/tex]
Generally the magnitude of the impulse delivered is mathematically represented as
[tex]I_1 = m* v_b - m * v_l[/tex]
=> [tex]I_1 = [0.145 * 45] - [0.145 * -53][/tex]
=> [tex]I_1 = 14.21 \ N\cdot s [/tex]
Considering the third question
The duration of the impact of the bat is [tex]t _1 = 0.7 \ ms = 0.7 *10^{-3} \ s[/tex]
Generally the average force exerted by the bat is mathematically represented as
[tex]F = \frac{I_1}{t_1}[/tex]
=> [tex]F = \frac{14.21 }{0.7 *10^{-3}}[/tex]
=> [tex]F = 20300 \ N [/tex]
A roller coaster at the Six Flags Great America amusement park in Gurnee, Illinois, incorporates some clever design technology and some basic physics. Each vertical loop, instead of being circular, is shaped like a teardrop. The cars ride on the inside of the loop at the top, and the speeds are fast enough to ensure that the cars remain on the track. The biggest loop is 40.0 m high. Suppose the speed at the top is 10.8 m/s and the corresponding centripetal acceleration is 2g. (a) What is the radius of the arc of the teardrop at the top
Answer:
5.95 m
Explanation:
Given that the biggest loop is 40.0 m high. Suppose the speed at the top is 10.8 m/s and the corresponding centripetal acceleration is 2g
For the car to stick to the loop without falling down, at the top of the ride, the centripetal force must be equal to the weight of the car. That is,
(MV^2) / r = mg
V^2/ r = centripetal acceleration which is equal to 2g
2 × 9.8 = 10.8^2 / r
r = 116.64 /19.6
r = 5.95 m
How much is the weight of a 1 kg mass at the pole and the equator of the earth
Given parameters:
Mass given = 1kg
Unknown:
Weight of the body at pole and equator = ?
Solution:
Both locations are on the surface of the earth. Generally, we take 9.8m/s² as the acceleration due to gravity on the earth.
Weight = mass x acceleration due to gravity
But little disparity occurs in the value of acceleration due to gravity from the pole to equator. This is due to equatorial bulge.
At the equator , 9.780 m/s²
pole 9.832 m/s²
Weight at equator = 1 x 9.780 = 9.78N
Weight at the pole = 1 x 9.832 = 9.832N
why does psychics need a electrical current
Answer:
Because Electrical Current is the most important thing about psychics
Explanation:
;p
a 50-kg object is acted upon by a net force of 360-N how much does it accelerate?
Answer:
it acceleration 7.2m/s²
Explanation:
mass of object = 50kg
force of object = 360N
acceleration = ?
Force= mass × acceleration
acceleration = force/mass
acceleration = 360N/50Kg
acceleration = 7.2m/s²
it accelerate 7.2 m/s²
In a totally inelastic collision between two equal masses, with one initially at rest, what fraction of the initial kinetic energy is lost
Answer:
50%
Explanation:
Assuming no external forces acting during the collision, total momentum must be conserved.As one of the mass was initially at rest, the initial momentum can be written as follows:[tex]p_{o} = m* v_{1o} (1)[/tex]
If the collision is totally inelastic, both masses must move as one after the collision, so we can write the following equation:[tex]p_{f} = (m+m)* v_{f} = 2*m*v_{f}[/tex] (2)As po = pf, we can solve for vf in terms of v1o, as follows:[tex]v_{f} =\frac{v_{1o}}{2}[/tex]
The initial kinetic energy will be:[tex]K_{1o} =\frac{1}{2} * m *v_{1o}^{2} (1)[/tex]
The final kinetic energy of both masses will be as follows:[tex]K_{f} =\frac{1}{2} * 2*m *(\frac{v_{1o}}{2}) ^{2} (2)[/tex]
Rearranging in (2) we get:[tex]K_{f} =\frac{1}{2} *m *v_{1o} ^{2} *\frac{1}{2} = \frac{K_{1o} }{2}[/tex]
So, the fraction of the initial kinetic energy lost is just the half of the initial value.Which of the following is man made and is used to store water for drinking or irrigation
Answer:
Reservoir.
Explanation:
The magnetic material is distributed this way because magnets
A
have magnetic fields that repel magnetic materials and push the shavings away.
B
have multiple magnetic fields that attract the shavings with different strengths.
C
have uneven magnetic fields that attract the shavings in random patterns.
D
have magnetic fields that flow from one pole of the magnet to the other.
Answer:
AExplanation:
Since one light is being taken away,
the rest of the light bulbs will get
more energy transfered to both
light bulbs, therefore, they will
not explode, but get brighter.
Hope this helps! <3
Since one light is being removed, more energy will be transmitted to the other light bulbs, preventing an explosion while increasing brightness. Thus, option B is correct.
What cause to magnetic fields?The majority of the electrons in some compounds, however, spin in the same direction due to their high magnetic properties.
These materials produce the strongest magnets due to their high magnetic permeability.
A magnet's magnetic strength is not the same throughout. In a bar magnet, the magnetic field is stronger around the pole than it is in the center, where the field is weaker.
This is so because the shape has an impact on how the magnetic energy in the area it occupies is distributed.
Therefore, have multiple magnetic fields that attract the shavings with different strengths.
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Convert 0.0000505 nanometers into scientific notation
Superman is riding his bicycle. At the base of a hill, he has a specific amount of kinetic energy. Then he coasts up the hill without pedaling. He comes to a stop at the top of the hill. Why is Superman’s potential energy at the top of the hill less than his kinetic energy at the bottom of the hill?
A. The hill did work on the bicycle as he went up the hill.
B. The rest of the energy is stored in the muscles of his body.
C. He still has kinetic energy while stopped on the top of the hill.
D. Friction and air resistance created heat on his trip up the hill.
Answer:
D. Friction and air resistance created heat on his trip up the hill.
Explanation:
Energy transformation from one form to another is not 100% efficient. This is the postulate of the first law of thermodynamics.
Most of the energy transformation is not purely 100%.
When energy is transformed, some are usually wasted.
In this case, in moving from bottom up, Superman produced some heat and encountered air resistance. To reach the top, he must have overcome the resistance and produce enough heat to power him through. This reduces the amount of potential energy that should have been the same as the kinetic energy down below.Explain how hypothesis are related to theories
A hypothesis is a prediction made prior to conducting research. It is constructed in such a way that it can be tested to see if it is true. A theory is a principle developed to explain what has already been observed in data.
What is hypothesis?A hypothesis is an explanation proposed for a phenomenon. The scientific method requires that a hypothesis be testable in order for it to be considered a scientific hypothesis.
Scientists typically base scientific hypotheses on previous observations that cannot be adequately explained by existing scientific theories.
Theories are frequently used by scientists, researchers, and psychologists to guide their research and develop hypotheses.
A theory must be supported by evidence, whereas a hypothesis guides research and aids in the collection of evidence.
A theory is a tested, well-substantiated, unifying explanation for a set of verified, proven factors in science. A theory is always supported by evidence, whereas a hypothesis is only a possible outcome that can be tested and falsified.
Thus, this way one can concluded that the hypothesis and theories are related.
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Laws of motion are important for the study of objects that are not in motion and objects in motion. Is it true or false?
Explain how to find the angle between two nonzero vectors. Choose the correct answer below. A. The angle between two nonzero vectors can be found by first dividing the dot product of the two vectors by the product of the twoâ vectors' magnitudes. Then taking the inverse cosine of the result. B. The angle between two nonzero vectors can be found by first dividing the product of the twoâ vectors' magnitudes by the dot product of the two vectors. Then taking the inverse cosine of the result. C. The angle between two nonzero vectors can be found by first dividing the dot product of the two vectors by the product of the twoâ vectors' magnitudes. Then taking the inverse sine of the result. D. The angle between two nonzero vectors can be found by first dividing the product of the twoâ vectors' magnitudes by the dot product of the two vectors. Then taking the inverse sine of the result.
Answer:
θ = Cos⁻¹[A.B/|A||B|]
A. The angle between two nonzero vectors can be found by first dividing the dot product of the two vectors by the product of the two vectors' magnitudes. Then taking the inverse cosine of the result
Explanation:
We can use the formula of the dot product, in order to find the angle between two non-zero vectors. The formula of dot product between two non-zero vectors is written a follows:
A.B = |A||B| Cosθ
where,
A = 1st Non-Zero Vector
B = 2nd Non-Zero Vector
|A| = Magnitude of Vector A
|B| = Magnitude of Vector B
θ = Angle between vector A and B
Therefore,
Cos θ = A.B/|A||B|
θ = Cos⁻¹[A.B/|A||B|]
Hence, the correct answer will be:
A. The angle between two nonzero vectors can be found by first dividing the dot product of the two vectors by the product of the two vectors' magnitudes. Then taking the inverse cosine of the result
how does a fly function in a energy pyramid
Answer:
A pyramid of energy shows the relative amount of energy available at each trophic level of a food chain or web. On average, about 10 percent of the energy available within one trophic level is transferred to the next level.
Explanation: