Answer:
Scientists have found the reason why our body temperature is 98.6°farehenheit (37°c). Apparently it's the perfect balance as it's warm enough to prevent fungal infection but not so hot that we need to eat nonstop to maintain our metabolism. ... So we know we need a higher body temperature to ward off fungal infection.
When light travels from air into water, Group of answer choices its wavelength changes, but its velocity and frequency does not change its velocity remains constant, but its frequency and wavelength changes its velocity, wavelength and frequency all change its velocity and wavelength changes, but its frequency does not change
Answer:
its velocity, wavelength and frequency all change
Explanation:
Whenever a wave crosses the boundary between two media of different densities, its velocity, frequency and wavelength changes. This appears as a bending of the wave as it crosses the boundary from one medium to another.
Refraction is a fundamental property of waves. Hence when light is travelling from air into water, it wavelength, speed and frequency all changes at the interface between the two media.
I need help pls now plleeeeeeeeaaassseeeee
Answer:
[tex]r = \frac{v}{i} = v = ri \\ i = \frac{v}{r} [/tex]
An archer shoots an arrow in the air, horizontally. However, after moving some
distance, the arrow falls to the ground. Name and define the initial force that sets
the arrow in motion. Explain why the arrow ultimately falls down.
Answer:
The name of the force is elastic (spring) force
Explanation:
The elastic force which is the restoration force of an elastic (spring like) object that tries to return to its initial non-stretched state built up by the pulling of the bow by the archer (using the muscles) pushes on the arrow which the archer releases the same time he leaves the bow string, and the arrow flies in the direction already pointed by the archer
The arrow ultimately falls down due to gravity forces that acts on all objects within the Earths gravitational field. However due to the speed of constant horizontal speed of the arrow and increasing downward speed of the due to the gravity force, the falling of the arrow looks disappointing.
A rock is thrown at a window that is located 16.0 m above the ground. The rock is thrown from the ground at an angle of 40.0° above horizontal with an initial speed of 30.0 m/s and experiences no appreciable air resistance. If the rock strikes the window on its upward trajectory, from what horizontal distance from the window was it released?
Answer:
x = 27.3 m
Explanation:
This is a projectile launching exercise, let's start by looking for the time it takes for the rock to reach the height of the window.
Let's use trigonometry to find the velocities of the rock
sin 40 = [tex]v_{oy}[/tex] / v
cos 40 = v₀ₓ / v
v_{oy}= v sin 40
v₀ₓ = v cos 40
v_{oy} = 30 sin 40 = 19.28 m / s
v₀ₓ = v cos 40
v₀ₓ = 30 cos 40 = 22.98 m / s
we look for the time
[tex]v_{y}^2[/tex] = v_{oy}^2 - 2 g y
v_{y}^2 = 19.28 2 - 2 9.8 16 = 371.71 - 313.6 = 58.118
v_{y} = 7.623 m / s
we calculate the time
v_{y} = v_{oy} - gt
t = (v_{oy} - v_{y}) / g
t = (19.28 -7.623) / 9.8
t = 1,189 s
since the time is the same for both movements let's use this time to find the horizontal distance
x = v₀ₓ t
x = 22.98 1,189
x = 27.3 m
what is physics and important of physics
Answer:
Confusion
question:
is it multiple choice? or you have to write it
Calculate the intensity of current flowing through a computer that consumes 180W and operates at 120 V.
A.)0,66 A
B.)12600 A
C.)1,5 A
D.)60 A
Answer:
C) 1.5 A
Explanation:
P = IV
180 W = I (120 V)
I = 1.5 A
A 2-kg cart, traveling on a horizontal air track with a speed of 3m/s, collides with a stationary 4-kg cart. The carts stick together. The impulse exerted by one cart on the other has a magnitude of
Answer:
The impulse exerted by one cart on the other has a magnitude of 4 N.s.
Explanation:
Given;
mass of the first cart, m₁ = 2 kg
initial speed of the first car, u₁ = 3 m/s
mass of the second cart, m₂ = 4 kg
initial speed of the second cart, u₂ = 0
Let the final speed of both carts = v, since they stick together after collision.
Apply the principle of conservation of momentum to determine v
m₁u₁ + m₂u₂ = v(m₁ + m₂)
2 x 3 + 0 = v(2 + 4)
6 = 6v
v = 1 m/s
Impulse is given by;
I = ft = mΔv = m(
The impulse exerted by the first cart on the second cart is given;
I = 2 (3 -1 )
I = 4 N.s
The impulse exerted by the second cart on the first cart is given;
I = 4(0-1)
I = - 4 N.s (equal in magnitude but opposite in direction to the impulse exerted by the first).
Therefore, the impulse exerted by one cart on the other has a magnitude of 4 N.s.
Self-Check
por Learning
A truck mass 8000 kg and a car a mass 1000
kg are travelling at the same velocity. Which one has greater kinetic energy ? Why?
Answer:
K.E of truck > K.E of car
Explanation:
Mass of the truck = 8000Kg
K.E=[tex]\frac{1}{2} mv[/tex]
K.E =[tex]\frac{1}{2}*8000*v\\ 4000v[/tex]
Mass of the car = 1000 Kg
K.E of the car =[tex]\frac{1}{2}*1000*v\\ 500v[/tex]
Therefore Kinetic energy of the truck is greater than that of the car
Students create a standing wave
with three loops on a slinky 3.75 m
long. They time 20 oscillations in
6.73 s. What is the wavelength of
the standing wave?
(Unit = m)
Explanation:
Given that,
Number of loops are 3
Length of slinky is 3.75 m
They time 20 oscillations in 6.73 s.
We need to find the wavelength of the standing wave.
For 3 loops, [tex]L=\dfrac{3\lambda}{2}[/tex]
Here, [tex]\lambda[/tex] is the wavelength of the standing wave
So,
[tex]\lambda=\dfrac{2L}{3}\\\\\lambda=\dfrac{2\times 3.75}{3}\\\\\lambda=2.5\ m[/tex]
So, the wavelength of the standing wave is 2.5 m.
Which waves move fast Longitudinal waves or Transverse waves and why???
Answer:
Transverse wave
Explanation:
Its because in transverse wave the particle displacement is perpendicular to the direction of wave propagation..hope it helps you...
Matter must have two physical properties 1. Have mass, and 2
∆ Must move
∆ Use energy
∆ Take up space
∆ Be measure
able
Answer:
Take up space
Explanation:
Actually we know this by the definition of matter which states that "matter is any substance that has mass and takes up space by having volume."
hope it helped you:)
Which are the two most popular candidates for gamma-ray bursters? Group of answer choices collisions between a white dwarf and a giant, and merger of two neutron stars hypernova making a black hole, and merger of two neutron stars formation of uranium in the core of a supergiant, and collisions of white dwarfs mergers of two black holes, and merger of a neutron star and a white dwarf hypernova making pulsars, and mergers of two white dwarfs
Answer:
hypernova making a black hole, and merger of two neutron stars
Shortly after receiving a traffic ticket for speeding, Fred made numerous comments about the road signs being inadequate and is GPS telling him a different speed limit. This would be an example of:
Answer:
External locus of control
Explanation:
External locus of control is an attitude people possess that makes them attribute their failures or successes to factors other than themselves. The opposite of this type of attitude is the Internal locus of control where the individuals take responsibility for the outcomes of their actions whether good or bad. One good thing about the external locus of control is that when the individuals with this characteristic record successes, they attribute it to others and this presents them as people with team spirit. However, when they record failures, they do not want to take the blame, but rather attribute it to others.
Fred exhibits an external locus of control because he attributed his speeding to other factors like the road signs and GPS instead of fully admitting that it was his fault.
High voltage power is often carried in wire bundles made up of individual strands. In your initial post to the discussion, discuss the forces on the strands of wire due to the current flowing through them. What would happen if the force acted opposite of the known behavior? Provide a detailed description.
Answer:
There will be a huge problem of holding the wire strands together, and the power losses will also be amplified.
Explanation:
The force per unit length on two current carrying conductors, lying parallel to each other is proportional to the product of the current through the conductors, and inversely proportional to their distance apart. This force is attractive if the current flows through these conductors in the same direction, and is repulsive if it flows in the opposite direction.
For the strand of wire that make up a high voltage wire bundle, there will be a force of attraction pulling the wires closer to each other, and they will experience the maximum pulling force possible, since they lie next to each other. This force helps to hold these wires in a high tension wire strand together, limiting the area, and reducing "skin effect."
In the case that this wires in the wire strand acts in opposite of the known behavior, the wires will repel and push each other apart. This pushing apart will increase power loss due "skin effect" which is increased by an increase in exposed surface area of the wire strands. This will pose a big problem for high tension transmission.
Match the words to the correct blanks in the sentences. Use each choice only once. a. The collapse of a protostar with less than 0.08 times the mass of the Sun is halted by________. b. As a protostar shrinks in size, its central temperature rises along with its________. c. A star that has not yet finished forming is called a_______. d. A forming star spins more rapidly as it collapses because of conservation of________. e. If a protostar has a mass too small for it to sustain nuclear fusion it becomes the type of object known as a________.A. thermal pressureB. angular momentumC. energy balanceD. degeneracy pressureE. brown dwarfF. gravitational equilibriumG. protostar
Answer:
The collapse of a protostar with less than 0.08 times the mass of the Sun is halted by DEGENERACY PRESSURE. b. As a protostar shrinks in size, its central temperature rises along with its THERMAL PRESSURE. c. A star that has not yet finished forming is called a__PROTOSTAR_____. d. A forming star spins more rapidly as it collapses because of conservation of ANGULAR MOMENTUM. e. If a protostar has a mass too small for it to sustain nuclear fusion it becomes the type of object known as a____BROWN DWARF____
to what temperature must a given mass of nitrogen at zero degrees be heated so both its volume and pressure will be doubled
Answer:
0 degrees Celsius is 273 degrees Kelvin. As both pressure and volume are proportional to absolute temperature, in order to double both you would need to quadruple the temperature. I.e. 273 X 4 = 1092 Kelvin = 819 Celsius
Explanation:
the distance between two successive troughs of wave is 0.4m. If the frequency of the source is 825Hz, calculate the speed of the wave
Answer:
speed=330m/s
Explanation:
the speed of wave is given as
speed(meter per second) =frequency(hertz) * wavelength(meters)
so using the above formula we substitute the figures given in the question in the formula we get
speed = 0.4*825
speed =330m/s
note m/s is the si unit for speed which is read as meter per second
therefore speed =330m/s
6. What are the methods to control noise pollution?
Answer: Some of the ways to control noise pollution are as follows: (1) Control at Receiver's End (2) Suppression of Noise at Source (3) Acoustic Zoning (4) Sound Insulation at Construction Stages (5) Planting of Trees (6) Legislative Measures.
Answer:
You have to:
a) Improve your insulation.
b) Install a fence
c) Use modern Acoustic wall panels
d) Plant trees
e) Reduce electronic volumes,e.t.c.
Explanation:
okay.
A narrow beam of light containing red (660 nm) and blue (470 nm) wavelengths travels from air through a 1.00 cm thick flat piece of crown glass and back to air again. The beam strikes at an incident angle of 30 degrees. (a) At what angles do the two colors emerge
Answer:
The color blue emerges at 19.16° and the color red emerges at 19.32°.
Explanation:
The angle at which the two colors emerge can be calculated using the Snell's Law:
[tex]n_{1}sin(\theta_{1}) = n_{2}sin(\theta_{2})[/tex]
Where:
n₁ is the refractive index of the incident medium (air) = 1.0003
n₂ is the refractive index of the refractive medium:
blue light in crown glass = 1.524
red light in crown glass = 1.512
θ₁ is the angle of the incident light = 30°
θ₂ is the angle of the refracted light
For the red wavelengths we have:
[tex] \theta_{2} = arcsin(\frac{n_{1}sin(\theta_{1})}{n_{2}}) = arcsin(\frac{1.0003*sin(30)}{1.512}) = 19.32 ^{\circ} [/tex]
For the blue wavelengths we have:
[tex] \theta_{2} = arcsin(\frac{n_{1}sin(\theta_{1})}{n_{2}}) = arcsin(\frac{1.0003*sin(30)}{1.524}) = 19.16 ^{\circ} [/tex]
Therefore, the color blue emerges at 19.16° and the color red emerges at 19.32°.
I hope it helps you!
A container contains 200g of water at initial temperature of 30°C. An iron nail of mass 200g at temperature of 50°C is immersed in the water. What is the final water temperature? State the assumptions you need to make in your calculations.
[Given the value of specific heat capacity of water is 4200 J kg^-1 °C^-1 and that of iron is
450 J kg^-1 °C^-1]
Answer:
The final temperature is 31.94°
Explanation:
The mass of the water in the container m₁ = 200 g = 0.2 kg
The initial temperature of the water, T₁₁ = 30°C
The mass of the iron, m₂ = 200 g = 0.2 kg
The temperature of the iron T₂₁= 50°C is immersed in the water,
The specific heat capacity of the water, c₁ = 4200 J/(kg·°C)
The specific heat capacity of the iron, c₂ = 450 J/(kg·°C)
Heat capacity relation is given by the formula;
Heat capacity Q = Mass, m × Specific heat capacity, c × Temperature change, (T₂ - T₁)
Given that energy can neither be created nor destroyed, and with the assumption that all the heat lost by the nail is gained by the water we have;
Heat lost by iron nail = Heat gained by the water
m₁ × c₁ × (T₂ - T₁₁) = m₂ × c₂ × (T₂₁ - T₂)
Where, T₂ is the final temperature
0.2 kg × 4200 J/(kg·°C) × (T₂ - 30) = 0.2 kg × 450 J/(kg·°C) × (50° - T₂)
840·T₂ - 25200 = 4500 - 90·T₂
4500 + 25200 = 840·T₂ + 90·T₂
29700 = 930·T₂
T₂ = 29700/930 = 31.94°.
The final temperature = 31.94°.
identify properties of a human body system
Answer:
integumentary, skeletal, muscular, nervous, endocrine, cardiovascular, lymphatic, respiratory, digestive, urinary, and reproductive
Explanation:
and this is biology not physics
A person holds a 25 kg (250 newton) bag of cement over his head and moves it a distance of 10 m, taking 2 minutes, while another person carries it on a wheelbarrow that same distance, taking 1 minute.Who does more work ? What is the power of each person?
Explanation:
Assuming the 10 m distance is the vertical displacement, the work done by both people is the same.
Work = force × distance
W = (250 N) (10 m)
W = 2500 J
The power of the first person is:
Power = work / time
P = 2500 J / 120 s
P = 20.83 W
The power of the second person is:
P = 2500 J / 60 s
P = 41.67 W
The law of conservation of momentum states that the total momentum of interacting objects does not _____. This means the total momentum _____a collision or explosion is equal to the total momentum _____ a collision or explosion.
Answer:
The law of conservation of momentum states that the total momentum of interacting objects does not change. This means the total momentum before a collision or explosion is equal to the total momentum after a collision or explosion.
Answer:
The answer is
Explanation:
Change. Does not change.means.
Hope this helps....
Have a nice day!!!!
1. Si tengo medio kilo de fruta y te doy un cuarto y tú me das tres cuartos de kilo, ¿cuánto tengo? 2. Si en una carrera te queda por recorrer la mitad de la mitad de 1 km, ¿cuánto te falta? 3. ¿Qué pesa mas, un kilo y medio de hierro o tres medios kilos de paja? porfavor es urgente.
Answer:
1. Tienes 1 kg de fruta.
2. Queda por recorrer 1/4 km.
3. Ambos pesan lo mismo.
Explanation:
1. Tienes 1/2 kg y cuando te doy 1/4 te queda:
[tex] m = \frac{1}{2} - \frac{1}{4} = \frac{1}{4} [/tex]
Ahora cuando te doy 3/4 kg te queda en total:
[tex] m_{T} = \frac{1}{4} + \frac{3}{4} = 1 kg [/tex]
Por lo tanto, tienes 1 kg de fruta al final.
2. Si falta por recorrer la mitad de la mitad, tenemos:
[tex] d = \frac{1/2}{2} = \frac{1}{4} [/tex]
Entonces, queda por recorrer 1/4 km.
3. El peso (P) del hierro es:
[tex] P = m*g [/tex]
[tex] P = (1 + 1/2)kg*9.81 m/s^{2} = 14.72 N [/tex]
Y el peso de la paja es:
[tex] P = 3/2 kg*9.81 m/s^{2} = 14.72 N [/tex]
Por lo tanto, ambos pesan lo mismo.
Espero que te sea de utilidad!
On a frictionless air track, a 0.30 kg glider moving at 0.40m/s to the right collides with a stationary 0.80kg glider moving at 0.15 m/s to the left. The collision is cushioned by a bumper made of perfectly elastic spring steel. a. What is the velocity of each glider after the collision? b. What is the minimum amount of total kinetic energy during the collision? c. Where is the missing energy?
Answer:
Explanation:
It is the case of perfectly elastic collision . So we shall apply formula of velocity after collision as follows .
Let m₁ and m₂ be the mass colliding with velocity u₁ and u₂ and their velocity become v₁ and v₂ after collision .
[tex]v_1=\frac{(m_1-m_2)u_1 }{m_1+m_2)} +\frac{2 m_2u_2}{(m_1+m_2)}[/tex]
Putting the values
[tex]v_1=\frac{ (.30-.80).40 }{( .30+.80)} +\frac{2\times .80\times(-.15) }{(.30+.80 )}[/tex]
= - 0.4 m /s
So direction of .30 kg mass will be reversed .
[tex]v_2=\frac{ ( m_2-m_1) u_2 }{( m_1+m_2)} +\frac{2 m_1u_1}{(m_1+m_2)}[/tex]
putting the values
[tex]v_2=\frac{ ( .80-.30)(-.15) }{( .30+.80)} +\frac{2 \times.30\times.40}{(.30+.80)}[/tex]
= .15 m /s
The direction of .80 kg will become from left to right ie its direction will be reversed .
b ) Minimum amount of kinetic energy will be at the position when they move with common velocity
common velocity
v = .3 x .4 - .8 x .15 / (.3 + .8)
= 0
c )
Missing energy is stored as elastic potential energy in the spring .
Can someone please illustrate how the refracted ray will look like?
Answer
As the angle of incidence increases in Figure 2.8, a point is finally reached where the refracted ray does not emerge at the second layer but lie along the interface. This particular angle of incidence at which the angle of refraction is 90° and the refracted ray lies along the interface is known as the critical angle. At and beyond the critical angle, there is no transmitted ray and therefore a very high reflected ray will be recorded .
Therefore,
sinθisin90=Vp1Vp2
But, sin 90 = 1.
At critical angle,
sinθcritical=Vp1Vp2
A critical refracted wave travels along the interface between layers and is refracted back into the upper layer at the critical angle. The waves refracted back into the upper layer are called head waves or first-break refractions because at certain distances from a source, they are the first arriving energy. Recorded first-break refraction is shown in Figure 2.10.
Note that these first-break refractions can give us important information about the shallow velocities on land seismic data.
Note also that seismic data are acquired in such a way that reflections from horizons of interest are in the pre-critical region, even at the farthest offset in the data.
In reality, part of the seismic energy arriving at an interface is transmitted and refracted, and another part of the energy is reflected at that same interface. Given that there are many reflectors in the subsurface, there will be many paths from source to receiver, each of them with a different travel time. The proportion of energy reflected depends on the material properties of the two bounding layers and on the angle of incidence
A construction worker uses an electrical device to attract fallen nails and sharp objects
from a construction site. What is causing the attraction of the metal objects?
O An electrical wave oscillating perpendicular to the electrical device.
O An electrical charge radiating perpendicular to the wire
O Amagnetic wave radiating perpendicular to an electrical device
O A magnetic wave and electrical current moving in opposite directions
Answer:
is the last one, a magnetic wave and electrical current moving in opposite directions
Explanation:
opposite directions always attract in magnetic waves and fields
This force governs atomic decay.
Answer:
The weak force governs the decay of a neutron into a proton (a process known as beta decay). The strong force binds quarks together into protons and neutrons (the residual strong force holds protons and neutrons together in the nucleus). Gravity governs the motion of an apple falling from a tree.
Explanation:
Answer:
Weak Nuclear force
The law of conservation of momentum states that the total momentum of interacting objects does not change . This means the total momentum a collision or explosion is equal to the total momentum a collision or explosion.what is momentum
Answer:
The momentum of an object is equal to the product of its mass and its velocity.
Explanation:
Consider an object of mass [tex]m[/tex] travelling at a velocity [tex]\vec{v}[/tex]. The momentum [tex]\vec{p}[/tex] of this object would be:
[tex]\vec{p} = m \cdot \vec{v}[/tex].
For the law of conservation of momentum, consider two objects: object [tex]\rm a[/tex] and object [tex]\rm b[/tex]. Assume that these two objects collided with each other.
Let [tex]m_{\rm a}[/tex] and [tex]m_{\rm b}[/tex] denote the mass of the two objects. Let [tex]\vec{v}_{\rm a}(\text{initial})[/tex] and [tex]\vec{v}_{\rm b}(\text{initial})[/tex] denote the velocity of the two object right before the interaction. Let [tex]\vec{v}_{\rm a}(\text{final})[/tex] and [tex]\vec{v}_{\rm b}(\text{final})[/tex] denote the velocity of the two objects right after the interaction. The momentum of the two objects right before the collision would be [tex]m_{\rm a}\cdot \vec{v}_{\rm a}(\text{initial})[/tex] and [tex]m_{\rm b}\cdot \vec{v}_{\rm b}(\text{initial})[/tex], respectively. The momentum of the two objects right after the collision would be [tex]m_{\rm a}\cdot \vec{v}_{\rm a}(\text{final})[/tex] and [tex]m_{\rm b}\cdot \vec{v}_{\rm b}(\text{final})[/tex], respectively.The sum of the momentum of the two objects would be:
[tex]m_{\rm a}\cdot \vec{v}_{\rm a}(\text{initial}) + m_{\rm b}\cdot \vec{v}_{\rm b}(\text{initial})[/tex] right before the collision, and[tex]m_{\rm a}\cdot \vec{v}_{\rm a}(\text{final}) + m_{\rm b}\cdot \vec{v}_{\rm b}(\text{final})[/tex] right after the collision.Assume that the system of these two objects is isolated. By the law of conservation of momentum, the sum of the momentum of these two objects should be the same before and after the collision. That is:
[tex]m_{\rm a}\cdot \vec{v}_{\rm a}(\text{initial}) + m_{\rm b}\cdot \vec{v}_{\rm b}(\text{initial}) = m_{\rm a}\cdot \vec{v}_{\rm a}(\text{final}) + m_{\rm b}\cdot \vec{v}_{\rm b}(\text{final})[/tex].
A speed that will permit a train or other equipment to stop within one half the range of vision short of a train, engine, railroad car, man or equipment fouling a track, stop signal or a derail or switch lined improperly. When a train or engine is required to move at restricted speed, the crew must keep a lookout for a broken rail and not exceed 20 mph:__________
Answer:
This is called restricted speed
