Hello,
QUESTION)Light is an electromagnetic wave, its speed is maximum in space and almost in the air where interactions have almost no effect. In other non-opaque media, light is subject to several phenomena: refraction and reflection. Part of the incident ray will be reflected in the same medium while the other part will be refracted in the new medium with a lower speed. In general, the medium influences the speed, and therefore the wavelength.
A baseball is traveling (+30m/s) and is hit by a bat. It leaves the bat traveling (−40m/s). What is the change in its velocity?
Unlike some others, this is any choice, so not just 4 choices!
Answer:
Explanation:
The change must be 30 - - 40 which means it came in a 30 meters / second and went out in the opposite direction at 40 meters / second
The change is 70 m/sec.
You could show it to be - 70 meters per second as well. That's done by making the outgoing direction minus.
Delta v = vf - vi.
Now it depends on which way you define vf and vi.
Which water on earth is the largest,second to the largest,3rd to the largest,fourth to the largest and 5th to the largest?
Answer:
Explanation:
There are a total of 5 differen classification for the types of bodies of water that exist on Earth. These 5 would be the following: Oceans, seas, lakes, rivers, and canals. Oceans are the biggest bodies of water on Earth. If we ranked them by their size the ranking would be the following...
Pacific Ocean - being 155,556,651 sq km. in size
Atlantic Ocean - being 76,761,938 sq km. in size
Indian Ocean - being 68,555,923 sq km. in size
Antarctic / Southern Ocean - being 20,327,001 sq km. in size
Arctic Ocean - being 14,055,930 sq km. in size
True or false—If a rock is thrown into the air, the increase in the height would increase the rock’s kinetic energy, and then the increase in the velocity as it falls to the ground would increase its potential energy.
If a rock is thrown into the air, the increase in the height would increase the rock’s kinetic energy, and then the increase in the velocity as it falls to the ground would increase its potential energy. _ This is false statement.
What is projectile motion?When a particle is hurled obliquely near the surface of the earth, it travels along a curved path while accelerating continuously in the direction of the planet's center (we assume the particle stays close to the surface of the globe). Such a particle's motion is known as projectile motion, and its route is referred to as a projectile.
In projectile motion total energy is conserved. Hence, when a rock is thrown into the air, the increase in the height would increase the rock’s potential energy, and then the increase in the velocity as it falls to the ground would increase its kinetic energy.
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ball A is dropped from a hot air balloon rising at a costant velocity of 14,7 m.s'1 at a height of 19,7 m above the ground.the ball took 1.5s to reach its maximum height and hits the ground after some time in air.ignore the effects of air resistanceUse the ground as zero reference.3.1.1calculate the maximum height reached by the ball above the ground
Answer:
this slow site thinks the answer is a link
Explanation:
this was a week ago so i dont know if u still need help
What color is a carrot?
Answer:
reddish-orrange
Explanation:
please mark me as brainliest
A child swings with a small amplitude on a playground with a 2.5m long chain.
a) what is the period of the child’s motion
b) what is the frequency of vibration
a. The period of the child's motion is 3.171 seconds.
b. The frequency of the vibration is 0.315 Hz.
Calculation of the period & frequency:Since A child swings with a small amplitude on a playground with a 2.5m long chain.
a. So here the time period should be
[tex]2\times \ pi(L/g)^{1/2}\\\\2\times 3.14(2.5/9.81)^{1/2}[/tex]
T=3.171s
b) Now the frequency is
[tex]T=1\div f\\\\f=1\div 3.171[/tex]
f=0.315Hz
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describe how electrons create electricity
describe how electrons create electricity
Atoms are made up of even smaller elements, called protons, electrons and neutrons. When electrical and magnetic forces move electrons from one atom to another, an electrical current is formed
Electrons in atoms can act as our charge carrier, because every electron carries a negative charge. If we can free an electron from an atom and force it to move, we can create electricity. ... In its balanced state, copper has 29 protons in its nucleus and an equal number of electrons orbiting around it.
Hope It Helps!
Which of the following is an example of the transformation of gravitational potential energy into motion energy (kinetic energy)?
Answer:
c
Explanation:
because a drop of water is falling and that is gravitational potential energy into motion energy
Why do scientists perform multiple trials of the same experiment?
Answer:
it's a good idea to do multiple trials, that is, do the same experiment lots of times. When we do multiple trials of the same experiment, we can make sure that our results are consistent and not altered by random events. Multiple trials can be done at one time.
Explanation:
the last one which is to increase the likelihood of accurate experiment results
Explanation:
10. John does 176 J of work lifting himself a distance of 0.40 m. How
much force must John apply to accomplish this?
O 440 m
O 440 J
O 440 N
O 70.4 J
Outline 3 disadvantages and advantage of water and alcohol as a template liquid
Answer:
Advantages of mercury as a thermometric liquid.
-It is a good conductor of heat and therefore the whole liquid reaches the temperature of the surroundings quickly.
-It does not wet (cling to the sides of) the tube.
-It has a high boiling point
-It expands uniformly (linear expansion) and responds quickly to temperature changes, hence is sensitive.
-It has a visible meniscus.
Disadvantages
-Mercury is very poisonous.
-its expansively is fairly low
-it is expensive
-It has a high freezing point therefore it cannot be used in places where the temperature gets very low.
Alcohol has a thermometric fluid
-Alcohol expands uniformly.
-It has a low freezing point (-115 degreecentigrade) therefore it is very suitable for place where the temperature gets very low.
-It has a large expansively
-It is an easily available cheap liquid, which is safe to use
Disadvantages of alcohol
-it wets the tube
-it has a low boiling point (cannot be used in places with high temperatures)
-it does not react quickly to changes in temperature
-It needs to be dyed, since it's colourless.
Disadvantages of water
-Water has high specific heat capacity. So it cannot be used for measuring small temperature differences.
- Water will wet the surface of the glass tube. It is a sticky substance.
- Water is transparent
Explanation:
Which resource when used causes the most pollution?
solar
coal
wind
O water
The bus lay 40 km at a speed of 72 km / h, and then another 60 km at a speed of 30 m / s. Determine the average speed of the bus along the way.
Answer:
25 m/s
Explanation:
From the question,
Average speed = Total distance /total time.
S' = D/T........................... Equation 1
D = 40+60 = 100 Km = 100000 m.
T = t₁+t₂
t₁ = (40×3600/72) s = 2000 s
t₂ = 60000/30 = 2000 s
T = 2000+2000 = 4000 s.
SUbstitute the values of T and D into equation 1
S' = 100000/4000
S' = 25 m/s
Assume a uniformly charged ring of radius R and charge Q produces an electric field Ering at a point P on its axis, at distance x away from the center of the ring. Now the charge Q is spread uniformly over the circular area the ring encloses, forming a flat disk of charge with the same radius. How does the field Edisk produced by the disk at P compare to the field produced by the ring at the same point?Assume a uniformly charged ring of radius R and charge Q produces an electric field Ering at a point P on its axis, at distance x away from the center of the ring. Now the charge Q is spread uniformly over the circular area the ring encloses, forming a flat disk of charge with the same radius. How does the field Edisk produced by the disk at P compare to the field produced by the ring at the same point?
Answer:
* E_ring = [tex]k \ \frac{x}{(x^2+ y^2)^{3/2} } \ Q[/tex]
*E_ disk= 2kQ [tex]\frac{1}{R^2} \ (1 - \frac{x}{(x^2+ R^2)^{1/2} } )[/tex]
Explanation:
Let's start by finding the electric field of the charged ring
in the attachment we can see a diagram of the system. Due to circular symmetry, the electric field perpendicular to the axis is canceled and only the electric field remains parallel to the axis.
Eₓ = E cos θ (1)
E = k ∫ [tex]\frac{dq}{r^2}[/tex]
cos θ = x / r
using the Pythagorean theorem
r = [tex]\sqrt{x^2 + y^2}[/tex]
we substitute
Eₓ = k ∫ [tex]\frac{dq}{x^2+y^2} \ \frac{x}{\sqrt{ x^2+y^2} }[/tex]
Eₓ = [tex]k \frac{x}{(c^2+y^2)^{3/2} }[/tex] ∫ dq
Eₓ = k \frac{x}{(c^2+y^2)^{3/2} } Q
the ring's electric field
E_ring = [tex]k \ \frac{x}{(x^2+ y^2)^{3/2} } \ Q[/tex]
Now let's find the electric field of the disk
The charge is distributed over the entire disk, so let's use the concept of charge density
σ = [tex]\frac{dq}{dA}[/tex]
Let's approximate the disk as a group of rings, the width of each ring is dr, the area is
dA = 2πr dr
we substitute
σ = [tex]\frac{1}{2\pi r} \ \frac{dq}{dr}[/tex]
dq = 2π σ r dr
we substitute in equation 1, where the electrioc field is of each ring
Eₓ = [tex]k \int\limits^R_0 \ { \frac{x}{(x^2+r^2)^{3/2} } \ 2\pi \sigma \ r } \, dr[/tex]
if we use a change of variable
dv = 2rdr
v = r²
Eₓ = [tex]k x \pi \sigma \int\limits^a_b { \frac{1}{(x^2+v)^{3/2} } } \, dv[/tex]
we integrate
Eₓ = k x π σ [tex][ \frac{ (x^2 + r^2)^{-1/2} }{-1/2} ][/tex]
we value in the limits from r = 0 to r = R
Eₓ = k π σ x (-2) [ [tex]\frac{1}{ \sqrt{x^2+R^2} } - \frac{1}{x}[/tex]]
Eₓ = 2π k σ ([tex]1 - \frac{x}{(x^2 + R^2 ) ^{1/2} }[/tex] )
σ = Q/πR²
substitute
Eₓ = 2 k Q/R² (1 - \frac{x}{(x^2 + R^2 ) ^{1/2} } )
E_ disk= 2kQ [tex]\frac{1}{R^2} \ (1 - \frac{x}{(x^2+ R^2)^{1/2} } )[/tex]
The two electric fields are
* E_ring = [tex]k \ \frac{x}{(x^2+ y^2)^{3/2} } \ Q[/tex]
*E_ disk= 2kQ [tex]\frac{1}{R^2} \ (1 - \frac{x}{(x^2+ R^2)^{1/2} } )[/tex]
we can see that the functional relationship of the two fields is different
What happens when a tennis racket hits
a ball?
A. The ball pushes back on the racket in the opposite
direction.
B. The ball pushes back on the racket in the same
direction.
C. The ball does not push back on the racket.
D. The ball pushes back on the racket perpendicularly.
Newton's third law of motion states that for every action, there is an equal and opposite reaction. When a tennis racket hits a ball A. The ball pushes back on the racket in the opposite direction.
When a tennis racket hits a ball, the ball exerts a force on the racket, and according to Newton's third law of motion, the racket exerts an equal and opposite force on the ball. This means that the ball pushes back on the racket in the opposite direction to which the racket struck the ball.
This principle is often referred to as "action-reaction" or "equal and opposite forces." When the racket collides with the ball, the force applied by the racket causes the ball to accelerate in the opposite direction, leading to its movement away from the racket.
Therefore, when a tennis racket hits a ball A. The ball pushes back on the racket in the opposite direction.
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Can you help me please here is the picture DUE NOW PLEASE.
they are formed when hot
it's dependent on the rate of cooling of the melt, slow cooling allows large crystals to form, fast cooling yields small crystals. They cool too quickly to form crystals.
Hope this helps! <3 :3
The parallel plates in a capacitor, with a plate area of 7.90 cm2 and an air-filled separation of 2.70 mm, are charged by a 7.90 V battery. They are then disconnected from the battery and pulled apart (without discharge) to a separation of 8.80 mm. Neglecting fringing, find (a) the potential difference between the plates, (b) the initial stored energy, (c) the final stored energy, and (d) the work required to separate the plates.
Answer:
A) 26V
Explanation:
(a) the potential difference between the plates
Initial capacitance can be calculated using below expresion
C1= A ε0/ d1
Where d1= distance between = 2.70 mm= 2.70× 10^-3 m
ε0= permittivity of space= 8.85× 10^-12 Fm^-1
A= area of the plate = 7.90 cm2 = 7.90 ×10^-4 m^2
If we substitute the values we
C1= A ε0/ d1
=( 7.90 ×10^-4 × 8.85× 10^-12 )/2.70× 10^-3
C1=2.589 ×10^-12 F= 2.59 pF
Initial charge can be determined using below expresion
q1= C1 × V1
V1=2.589 ×10^-12 F
V1= voltage=7.90 V
If we substitute we have
q1= 2.589 ×10^-12 × 7.90
q1= 20.45×10^-12C
20.45 pC
Final capacitance can be calculated as
C2= A ε0/ d2
d2=8.80 mm= /8.80× 10^-3
7.90 ×10^-4 × 8.85× 10^-12 )/8.80× 10^-3
C1=0.794 ×10^-12 F= 0.794 pF
Final charge= initial charge
q2=q1 (since the battery is disconnected)
q2=q1= 20.45 pC
Final potential difference
V2= q/C2
= 20.45/0.794
= 26V
what is the magnitude of electric field at apoint 2 meter from a point charge q= 4nc
Which is a primary energy source used by power plants to generate electricity?
coal
O wood
o gasoline
batteries
Answer:
Your answer is wood that is what they used
The primary energy source used by power plants to generate electricity is coal.
What are power plants?Power plants are plants which use fuels to generate electricity for use by homes and industries.
Power plants have different energy sources for their fuel.
The primary energy source used by power plants to generate electricity is coal.
Therefore, coal is a primary source of fuel for power plants.
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a)Hari drove for 2 hours at a speed of 60km/h and next3 hours at a speed of 70km/h. Calculatehis average speed for the whole journey.b)A police car drives with a constant speed of 70km/h. How long it will take to cover a distance of 135 km? Express the speed in m/s
Answer:
Remember the relation:
Speed*Time = Distance.
Then first let's find the total distance that Hari drove.
First, he droves 2 hours at 60km/h, then the total distance traveled is:
Distance = 2h*60km/h = 120km
Then he droves 3 hours at 70km/h
The distance here is:
Distance = 3*70km/h = 210km
The total distance traveled is 120km + 210km = 330km
The total time of the travel is 2 hours + 3 hours = 5 hours.
The average speed is calculated as:
Av speed = (total distance)/(total time)
Av speed = (330km)/(5 h) = 66km/h
The average speed is 66km/h.
b) We know that the speed is 70km/h, but we want to write this in m/s.
Then we first know that 1 km = 1000m
then:
1 = (1000m/1km)
Then 70km/h = 70 km/h*(1000m/1km) = (70*1000) m/h = 70,000 m/h
Now we know that 1h = 3600 seconds, then:
1 = (1h/3600s)
So we can write:
70,000 m/h = (70,000 m/h)* (1h/3600s) = 70,000/3600 m/s = 0.019 m/s
and the distance is 135 km
Again, we can rewrite this as:
135km = 135km*(1000m/1km) = 135,000m
Then we want to solve:
(0.019m/s)*time = 135,000 m
We want to solve this for the time, then we get:
time = (135,000m)/(0.019m/s) = 7,105,263.2 seconds = 1.93 hours
A 65 kg cart travels at a constant speed of 4.6 m/s. What is its kinetic energy?
Answer:
Explanation:
mass (m) = 65 kg
velocity (v) = 4.6 m/s
Kinetic energy (KE)
= 1/2 * m * v²
= 1/2 * 65 * 4.6²
= 687.7 J
hope it helps :)
Your heart pumps blood into your aorta (diameter 2.5 cm) with a maximum flow rate of about 500 cm^3/s. Assume that blood flow in the aorta is laminar (which is not a very accurate assumption) and that blood is a Newtonian fluid with a viscosity similar to that of water.
a. Find the pressure drop per unit length along the aorta. Compare the pressure drop along a 10 cm length of aorta to atmospheric pressure (105 Pa).
b. Estimate the power required for the heart to push blood along a 10 cm length of aorta, and compare to the basal metabolic rate of 100 W.
c. Determine and sketch the velocity profile across the aorta (assuming laminar flow). What is the velocity at the center
Answer:
a. i) The pressure drop per unit length is 52,151.89 Pa
ii) The atmospheric pressure ≈ 19.175 × The pressure drop along 10 cm length of aorta
b i) The power required for the heart to push blood along a 10 cm length of aorta, is 2.6075945 Watts
ii) The basal metabolic rate ≈ 38.35 × The power to push the blood along a 10 cm length of aorta
c. i) Please find attached the drawing for the velocity profile created with Microsoft Excel
ii) The velocity at the center is approximately 2.04 m/s
Explanation:
The given diameter of the aorta, D = 2.5 cm = 0.025 m
The maximum flow rate, Q = 500 cm³/s = 0.0005 m³/s
Assumptions;
The blood flow is laminar
The blood is a Newtonian fluid
The viscosity of water ≈ 0.01 poise = 1 cp
a. i) The pressure drop per unit length of pipe ΔP/L is given by the Hagen Poiseuille equation as follows;
[tex]Q = \dfrac{\pi \cdot R^4}{8 \cdot \mu} \cdot \left(\dfrac{\Delta p}{L} \right)[/tex]
Where;
Q = The flow rate = A·v
A = The cross sectional area
R = The radius = D/2
Δp/L = The pressure drop per unit length of the pipe
Therefore, we have;
[tex]\dfrac{\Delta p}{L} = \dfrac{Q\cdot 8 \cdot \mu }{\pi \cdot R^4} = \dfrac{0.0005 \times 8 \times 1}{\pi \times 0.0125^4 } = 52151.89[/tex]
The pressure drop per unit length ΔP/L = 52,151.89 Pa
ii) The pressure, ΔP, drop along 10 cm (0.1 m) length of aorta = ΔP/L × x;
∴ ΔP = 52,151.89 Pa × 0.1 m = 5,215.189 Pa
Given that the atmospheric pressure, [tex]P_{atm}[/tex] = 10⁵ Pa, we have;
[tex]P_{atm}[/tex]/ΔP = 10⁵/5,215.189 ≈ 19.175
Therefore, the atmospheric pressure is approximately 19.175 times the pressure drop along 10 cm length of aorta
b. i) The power, P = Q × ΔP
Therefore, the power required for the heart to push blood along a 10 cm length of aorta, is P₁₀ = 0.0005 m³/s × 5,215.189 Pa = 2.6075945 Watts
ii) Therefore compared to the basal metabolic rate of, 'P', 100 W, we have;
P/P₁₀ = 100 W/2.6075945 Watts = 38.349521 ≈ 38.35
The basal metabolic rate is approximately 38.35 times more powerful than the power to push the blood along a 10 cm length
c. i) The velocity profile across the aorta is given as follows;
[tex]v_m = \dfrac{1}{4 \cdot \mu} \cdot \dfrac{\Delta P}{L} \cdot R^2[/tex]
Where;
[tex]v_m[/tex] = The velocity at the center
We get;
[tex]v_m = \dfrac{1}{4 \times 1} \times 52,151.89 \times 0.0125^2 \approx 2 .04[/tex]
The velocity at the center, [tex]v_m[/tex] ≈ 2.04 m/s
ii) The velocity profile, v(r), is given by the following formula;
[tex]v(r) = v_m \cdot \left[1 - \dfrac{r^2}{R^2} \right][/tex]
Therefore, we have;
[tex]v(r) = 2.04 - \dfrac{2.04 \cdot r^2}{0.0125^2} \right] = 2.04 - 163\cdot r^2[/tex]
The velocity profile of the pipe is created with Microsoft Excel
3. A backpack weighs 8.2 N and has a mass of 5 kg on the moon. What is t
strength of gravity on the moon?
8.2 N
Define electromagnetism
Answer:
the phenomenon of the interaction of electric currents or fields and magnetic fields.
In fatal crashes, more than __________% of passenger car occupants who were totally ejected from the vehicle were killed.
Answer:
it would be 83% in a fatal crash.
why is gravity on earth important
10. A 50 kg bicyclist on a 10 kg bicycle speeds up from 5.0 m/s to 10 m/s.
(a) What was the total kinetic energy before accelerating? Full working out
Answer:
T.K.E = 750 Joules.
Explanation:
Given the following data;
Initial velocity, u = 5m/s
Final velocity, v = 10m/s
Mass of bicyclist = 50kg
Mass of bicycle = 10kg
Total mass, Tm = 50 + 10 = 60kg
Kinetic energy can be defined as an energy possessed by an object or body due to its motion.
Mathematically, kinetic energy is given by the formula;
[tex] K.E = \frac{1}{2}mv^{2}[/tex]
Where;
K.E represents kinetic energy measured in Joules.
m represents mass measured in kilograms.
v represents velocity measured in metres per seconds square.
To find the total kinetic energy before accelerating simply means the kinetic energy due to the initial velocity and total mass;
[tex] T.K.E = \frac{1}{2}T_{m}U^{2}[/tex]
Substituting into the equation, we have;
[tex] T.K.E = \frac{1}{2}*60*5^{2}[/tex]
[tex] T.K.E = 30*25 [/tex]
T.K.E = 750 Joules.
5j-Tj=6j+3 Tj
Determine the value of T from the given vector
The surveillance camera on a satellite at 250 km above the earth is taking pictures of the earth surface. Suppose that the imaging wavelength is 550 nm and the diameter of the camera lens is 40 mm. (a) Calculate the angular resolution of the camera. (b) Suppose that the headlights of a car on the earth are 1.6 m apart, can the camera resolve them
Answer:
a) θ = 1.67 10⁻⁵ m, b) Consequently we must affirm that the vehicle headlights cannot resolve.
Explanation:
a) To find the resolution of the camera we use the Rayleigh criterion for diffraction
a sin θ = m λ
where m = 1 for the first zero of the slit
we must remember that the angles in the experiments are measured in radians and are very small
sin θ = θ
we substitute
θ = [tex]\frac{\lambda}{a}[/tex]
this expression is for a slit, in the case of circular openings the expression must be solved in polar coordinates giving
θ = [tex]1.22 \ \frac{\lambda}{D}[/tex]
where D diameters of the opening
let's calculate
θ = [tex]1.22 \ \frac{550 \ 10^{-9}}{ 40\ 10^{-3}}[/tex]
θ = 1.67 10⁻⁵ m
b) let's use trigonometry to find the separation distance on earth
tan θ = y / x
y = x tan θ
let's calculate
remember that the angles must be in radians
y = 250 10³ tan 1.67 10⁻0-5
y = 4.18 m
as they indicate that the separation of the headlights is y = 1.6m,
we see that this separation is greater than the separation distance separation.
Consequently we must affirm that the vehicle headlights cannot resolve.
A marching band consists of rows of musicians walking in straight, even lines. When a marching band performs in an event, such as a parade, and must round a curve in the road, the musician on the outside of the curve must walk around the curve in the same amount of time as the musician on the inside of the curve. This motion can be approximated by a disk rotating at a constant rate about an axis perpendicular to its plane. In this case, the axis of rotation is at the inside of the curve. Consider two musicians, Alf and Beth. Beth is four times the distance from the inside of the curve as Alf. Knowing that If Beth travels a distance s during time Δt, how far does Alf travel during the same amount of time= (1/4)s
If Alf moves with speed v, what is Beth's speed?
a. 4v
b. v
c. v/4
Answer:
A) Total distance Alf travel during the same amount of time = [tex]\frac{1}{4}s[/tex]
B) Speed of Beth = 4v
Explanation:
Given - Consider two musicians, Alf and Beth. Beth is four times the
distance from the inside of the curve as Alf.
To find - A) Knowing that If Beth travels a distance s during time Δt, how
far does Alf travel during the same amount of time.
B) If Alf moves with speed v, what is Beth's speed?
Proof -
A)
As we know that
Speed = Distance / Time
⇒Distance = Speed ×Time
Now,
Given Speed of Alf = v
⇒Distance of Alf = vt
Also,
Distance of Beth = Speed of beth×time
Given that
Beth is four times the distance from the inside of the curve as Alf. Knowing that If Beth travels a distance s during time Δt, how far does Alf travel during the same amount of time=
⇒Distance of Alf = Speed of Alf×time
= [tex]\frac{1}{4}[/tex] Distance of Beth
⇒Distance of Alf = [tex]\frac{1}{4}s[/tex]
∴ we get
Total distance Alf travel during the same amount of time = [tex]\frac{1}{4}s[/tex]
B)
We know the conversion of angular velocity
ω(Alf) = ω(Beth)
⇒V(Alf)/ r = V(Beth)/4r
⇒V(Alf) = V(Beth) / 4
⇒V(Beth) = 4 V(Alf)
As given, Alf moves with speed v
⇒V(Beth) = 4v
So, the correct option is - a.4v