Answer:
The value is [tex]\theta = 34.40^o[/tex]
Explanation:
From the question we are told that
The index of refraction is [tex]n_s = 1.77[/tex]
The refractive index of air is [tex]n_a = 1.0[/tex]
Generally the critical angle is mathematically represented as
[tex]\theta = sin ^{-1} [\frac{1}{n_s} ][/tex]
=> [tex]\theta = sin ^{-1} [\frac{1}{1.77} ][/tex]
=> [tex]\theta = sin ^{-1} [0.565 ][/tex]
=> [tex]\theta = 34.40^o[/tex]
A fish in an aquarium with flat sides looks out at a hungry cat. To the fish, the distance to the cat appears to be
Answer:
flat
Explanation:
A student performed an experiment with a metal sphere. The student shot the sphere from a slingshot and measured its maximum height. Six different trials were performed with the sphere being shot at a different angle from the horizontal for each trial. What is the independent variable
The correct answer is Launch angle
Explanation:
The Independent Variable can be easily identified because this is the factor or variable the researcher modifies. In this case, this term applies to the angle because as part of the experiment the student changes the angle multiple times to test how the maximum height changes. Moreover, the maximum height would be the dependent variable as it is the main factor and it changes or depends on other variables including the angle. Thus, it can be concluded the independent variable is the launch angle or the angle from which the ball is launched.
ohms law? explanation.
Answer:
[tex] \boxed{ \bold{ \sf{see \: below}}}[/tex]
Explanation:
[tex] \boxed{ \bold{ \underline{ \huge{ \boxed{ \sf{ohm's \: law}}}}}}[/tex]
The relation between current through a metallic conductor and potential difference across its ends was studied systematically by a German physicist , George Simon Ohm in 1826 AD . This relation is now known as Ohm's law. It states that the electric current passing through a conductor is directly proportional to the potential difference across its two ends at a constant physical condition [ Temperature , cross - sectional area , length , nature of material etc ]
Hope I helped!
Best regards!!
Why won’t a magnet help you separate a mixture of salt and water
Answer: nor are magnetic
Answer: Neither salt or water are magnetized.
Explanation: The best way to separate salt and water is to boil the mixture. If you wanted to use a magnet you would need something magnetized, like iron fillings.
What is the relationship between power and bulb brightness (intensity)?
Explanation:
Power of an electrical appliance is given by :
P = VI
Here,
V is the voltage
I is the current
From the above formula for power, we find that power is directly proportional to the voltage of the circuit. If a single bulb is there in the circuit, increasing the voltage of the bulb will increase its power, which in turn increases its bulb brightness or intensity.
Two positive point charges, each with charge q, separated by a distance d, repel each other with a force of magnitude 20 N. What is the magnitude of the force between two positive point charges of magnitude 11.11 q, separated by a distance 2.5 d in units of N
Answer:
The value is [tex]F_2 = 395 \ N[/tex]
Explanation:
From the question we are told that
The magnitude of the charge of each positive charge for the first case is [tex]q_1 = q_2 = q[/tex]
The distance between the charges for the first case is [tex]d[/tex]
The force between the charges for the first case is [tex]F = 20 \ N[/tex]
The magnitude of the charge of each positive charge for the second case is [tex]q_1 = q_2=11.11q[/tex]
The distance between the charge for the second case is [tex]2.5d[/tex]
Generally for the first case the force between the charge is mathematically represented as
[tex]F_1 = \frac{k * q^2 }{d^2}[/tex]
Where k is the Coulomb constant with value [tex]k = 9*10^{9} \ kg\cdot m^3\cdot s^{-4} \cdot A^{-2}.[/tex]
So
[tex]20= \frac{k * q^2 }{d^2}[/tex]
Generally for the second case the force between the charge is mathematically represented as
[tex]F_2 = \frac{k * (11.11q)^2}{(2.5d)^2}[/tex]
[tex]F_2 = \frac{k * 11.11^2 *q^2}{2.5^2d^2}[/tex]
=> [tex]F_2 = \frac{11.11^2}{2.5^2} F_1[/tex]
=> [tex]F_2 = \frac{11.11^2}{2.5^2} * 20[/tex]
=> [tex]F_2 = 395 \ N[/tex]
The phase velocity of transverse waves in a crystal of atomic separation a is given byy = csin(ka/2) pka/2 1. What is the dispersion relation e(k)? 2. What is the group velocity as a function of k?
Answer:
a
e(k) = \frac{2a}{c} * sin (\frac{k*a}{2} )
b
G_{v} = \frac{d e(k ) }{dk } = \frac{a^2}{c} * cos (\frac{k* a}{2} )
Explanation:
From the question we are told that
The velocity of transverse waves in a crystal of atomic separation is
[tex]b_y = c \frac{sin (\frac{k*a}{2} )}{\frac{k*a}{2} }[/tex]
Generally the dispersion relation is mathematically represented as
[tex]e(k) = b_y * k[/tex]
=> [tex]e(k) = c \frac{sin(\frac{k*a}{2} ) }{ \frac{k*a}{2} } * k[/tex]
=> [tex]e(k) = c * \frac{sin (\frac{k_a}{2} )}{ \frac{a}{2} }[/tex]
=> [tex]e(k) = \frac{2a}{c} * sin (\frac{k*a}{2} )[/tex]
Generally the group velocity is mathematically represented as
[tex]G_{v} = \frac{d e(k ) }{dk } = \frac{a^2}{c} * cos (\frac{k* a}{2} ) [/tex]
You hike two thirds of the way to the top of a hill at a speed of 2.9 mi/h and run the final third at a speed of 5.6 mi/h. What was your average speed?
Answer:
The average speed is 3.5 mi/h
Explanation:
Average speed is given by
[tex]Average speed = \frac{Total distance}{Total time}[/tex]
If the total distance covered is [tex]x[/tex] mi,
Then [tex]\frac{2}{3}x[/tex] mi was covered while hiking and
[tex]\frac{1}{3}x[/tex] mi was covered while running.
Now, we will find the time taken while hiking and the time taken while running
[tex]Speed = \frac{Distance}{ Time}\\ Time = \frac{Distance}{Speed}[/tex]
For the time taken while hikingSpeed = 2.9 mi/h
Distance = [tex]\frac{2}{3}x[/tex] mi
From,
[tex]Time = \frac{Distance}{Speed}[/tex]
[tex]Time = \frac{\frac{2}{3}x }{2.9}[/tex]
Time = [tex]0.2299x[/tex] h
Time taken while hiking is 0.2299 h
For the time taken while runningSpeed = 5.6 mi/h
Distance = [tex]\frac{1}{3}x[/tex] mi
[tex]Time = \frac{Distance}{Speed}[/tex]
[tex]Time = \frac{\frac{1}{3}x }{5.6}[/tex]
Time = [tex]0.05952x[/tex] h
Now, for the average speed
[tex]Average speed = \frac{Total distance}{Total time}[/tex]
Total distance = [tex]\frac{2}{3}x[/tex] mi + [tex]\frac{1}{3}x[/tex] mi = [tex]x[/tex] mi
Total time = [tex]0.2299x[/tex] + [tex]0.05952x[/tex] = [tex]0.28942x[/tex] h
∴ [tex]Average speed = \frac{x}{0.28942x}[/tex]
Average speed = 3.4552 mi/h
Average speed ≅ 3.5 mi/h
Which scenario is an example of a physical change?
Wood is burned in a campfire and is turned into ash and smoke.
A piece of metal is left in the rain and forms rust.
Lead is melted into a liquid to form pellets.
Yeast turns sugar into energy, water, and carbon dioxide gas.
Answer:
Lead is melted into a liquid to form pellets.
Answer:
C. lead is melted into a liquid to form pellets
Explanation:
Which parenting style is thought to produce children who grow up to be emotionally withdrawn,
distant, and lacking in curiosity?
Answer:
Uninvolved parenting style
Explanation:
Uninvolved parenting style is the parenting style which is thought to produce children who grow up to be emotionally withdrawn, distant, and lacking in curiosity.
This is usually because there is little or no contact between the parents and children which leaves a wide gap and the children start to become emotionally withdrawn as a result. They also aren’t curious to learn new things as a result of the absence of parental care.
If we put negative charge between two similar positive charges then what is it's equilibrium? And how?
Your question has been heard loud and clear.
Well it depends on the magnitude of charges. Generally , when both positive charges have the same magnitude , their equilibrium point is towards the centre joining the two charges. But if magnitude of one positive charge is higher than the other , then the equilibrium point will be towards the charge having lesser magnitude.
Now , a negative charge is placed in between the two positive charges. So , if both positive charges have same magnitude , they both pull the negative charge towards each other with an equal force. Thus the equilibrium point will be where the negative charge is placed because , both forces are equal , and opposite , so they cancel out each other at the point where the negative charge is placed. However if they are of different magnitudes , then the equilibrium point will be shifted towards the positive charge having less magnitude.
Thank you
Answer:
it will be positive
Explanation:
Calculate the reactance of a 0.5 F capacitor that is connected to a battery with peak voltage 2 V and angular frequency 200 radians/s.
Answer:
Reactance of the capacitor is 0.01 ohms.
Explanation:
It is given that,
Capacitance of the capacitor is 0.5 F
Peak voltage of the battery is 2 V
Angular frequency is 200 rad/s
We need to find the capacitive reactance. The capacitive reactance is due to the capacitor in the circuit. It is given by :
[tex]X_c=\dfrac{1}{\omega C}\\\\X_c=\dfrac{1}{200\times 0.5}\\\\X_c=0.01\ \Omega[/tex]
So, the reactance is 0.01 ohms.
An apple is thrown at an angle of 30° above the horizontal from the top of a building 20 m high. Its initial speed is 40 ms-1. Calculate
a)the time taken for the apple to strikes the ground
b) the distance from the foot of the building will it strikes the ground
c) the maximun height reached by the apple from the ground
Answer:
(a) 4.83 seconds
(b) 167.3m
(c) 40m
Explanation:
This is a two-dimensional motion. Therefore, the components of the initial velocity - [tex]u_X[/tex] and [tex]u_Y[/tex] - in the x and y directions are given as follows:
[tex]u_X[/tex] = u cos θ --------------(*)
[tex]u_Y[/tex] = u sin θ -------------(**)
Where
θ = angle of projection
(a) To calculate the time taken for the apple to strike the ground.
For simplicity, let's first calculate the maximum height H reached by the apple.
Using one of the equations of motion as follows, we can find H:
v² = u² + 2as ---------------(i)
Where;
v = velocity at maximum height = 0 [at maximum height, velocity is 0]
u = initial vertical velocity of the apple = [tex]u_Y[/tex]
=> u = [tex]u_Y[/tex] = u sin θ
=> [tex]u_Y[/tex] = 40 sin 30°
=> [tex]u_Y[/tex] = 40 x 0.5
=> [tex]u_Y[/tex] = 20 m/s
a = acceleration due to gravity = -g [apple moves upwards against gravity]
a = -10m/s²
s = H = maximum height reached from the top of the building
Substitute these values into equation (i) above to have;
0² = [tex]u_Y[/tex]² + 2aH
0² = (20)² + 2(-10)H
0 = 400 - 20H
20H = 400
H = 20m
The total time taken to strike the ground is the sum of the time taken to reach maximum height and the time taken to strike the ground from maximum height.
=>Calculate time t₁ to reach maximum height.
Using one of the equations of motion, we can calculate t₁ as follows;
v = [tex]u_Y[/tex] + at ---------------(ii)
Where;
v = velocity at maximum height = 0
u = initial vertical velocity of the apple = [tex]u_Y[/tex]
a = -g = -10m/s² [acceleration due to gravity is negative since the apple is thrown upwards to reach maximum height]
t = t₁ = time taken to reach maximum height.
Equation (ii) then becomes;
0 = 20 + (-10)t₁
10t₁ = 20
t₁ = 2 seconds
=>Calculate time t₂ to strike the ground from maximum height.
Now, using one of the equations of motion, we can calculate the time taken as follows;
Δy = [tex]u_Y[/tex] t + [tex]\frac{1}{2}[/tex]at ---------------(iii)
Where;
Δy = displacement from maximum height to the ground = maximum height from top of building + height of building = 20 + 20 = 40m
a = g = 10m/s² [acceleration due to gravity is positive since the apple is now coming downwards from maximum height]
t = t₂ [time taken to strike the ground from maximum height]
[tex]u_Y[/tex] = initial vertical velocity from maximum height = 0
[tex]u_Y[/tex] = 0
Equation (iii) then becomes
40 = 0t + [tex]\frac{1}{2}[/tex](10)t₂²
40 = 5t₂² [divide through by 5]
8 = t₂²
t₂ = ±[tex]\sqrt{8}[/tex]
t₂ = ±[tex]2\sqrt{2}[/tex]
t₂ = +2[tex]\sqrt{2}[/tex] or -2[tex]\sqrt{2}[/tex]
since time cannot be negative,
t₂ = 2[tex]\sqrt{2}[/tex] = 2.83 seconds
Therefore, the time taken for the apple to strike the ground is;
t₁ + t₂ = 2 + 2.83 = 4.83 seconds
(b) The distance from the foot of the building where the apple will strike the ground
Since this is the horizontal distance, we use the horizontal version of equation (iii) as follows;
Δx = [tex]u_X[/tex] t + [tex]\frac{1}{2}[/tex]at -----------(v)
Where
Δx = distance from the foot of the building to where the apple strikes the ground.
[tex]u_X[/tex] = initial horizontal velocity of the apple as expressed in equation (*)
[tex]u_X[/tex] = 40 cos 30
[tex]u_X[/tex] = 34.64 m/s
t = time taken for the motion of the apple = 4.83 seconds [calculated above]
a = acceleration due to gravity in the horizontal direction = 0. [For a projectile, there is no acceleration in the horizontal direction since velocity is constant]
Substitute these values into equation (v) as follows;
Δx = [tex]u_X[/tex] t + [tex]\frac{1}{2}[/tex](0)t
Δx = 34.64 x 4.83
Δx = 167.3 m
Therefore, the distance from the foot of the building is 167.3m
(c) The maximum height reached by the apple from the ground
This is the sum of the height reached from the top of the building (20m which has been calculated in (a) above) and the height of the building.
= 20m + 20m = 40m
what would most likely cause the future accelaration of the expansion of the univers
Answer: radiation from the Sun the existence of background radiation the continued existence of dark energy light shifts identified by the Doppler effect.
Explanation:
A spherically spreading EM wave comes from an 1800-W source. At a distance of 5.0 m, what is the intensity, and what is the rms value of the electric field?
Answer:
The intensity of the EM wave is 5.729 W/m²
The rms value of the electric field is 46.452 V/m
Explanation:
Given;
power of the electromagnetic wave, P = 1800 W
The intensity of light is given by;
I = P / A
Where;
A is the surface area of the sphere = 4πr²
A is the surface area of the sphere = 4π(5)²
A is the surface area of the sphere = 314.2 m²
The intensity is calculated as;
I = P / A
I = (1800) / (314.2)
I = 5.729 W/m²
The rms value of the electric field is given by;
[tex]E_{rms} = \sqrt{\frac{I}{c \epsilon _o}}\\\\E_{rms} = \sqrt{\frac{5.729}{(3*10^8)( 8.85*10^{-12})}}\\\\E_{rms} = 46.452 \ V/m[/tex]
__________ have large spaces between high energy particles.
Ions
Liquids
Gases
Solids
Answer:
the answer should be gasses
Since the noble gases are stable (VERY unreactive), oxygen would like to look like one in terms of the number and arrangement of its electrons. What would the atom of oxygen have to do to its electrons in order to look like neon?
Answer:
oxygen gains two electron to attain electron configuration like neon. Oe-²
Explanation:
______ Daltons model (it was no longer a solid, indivisible sphere)
Answer:
John
Explanation:
John Dalton is the scientist with the atomic model.
Answer:
John Daltons atomic model
Explanation:
A cheetah can run at a top speed of 85 mi/h . What is the distance it runs in half an hour?
Answer:
42.5 miles
Explanation:
To find the answer we need to know the formula:
Distance = speed x time
85 x 0.5 = 42.5 miles
Hope this helps!
If you run at a constant speed of 7.5 m/s, how long does it take for you to finish a 100 m race ? show your work
Answer:
13s
Explanation:
(7.5m/s)(t)=(100m)
t=(100/7.5)s=13s
how does the earth release energy back into the atmosphere?
Answer:
Explanation:
The earth-atmosphere energy balance is the balance between incoming energy from the Sun and outgoing energy from the Earth. Energy released from the Sun is emitted as shortwave light and ultraviolet energy. When it reaches the Earth, some is reflected back to space by clouds, some is absorbed by the atmosphere, and some is absorbed at the Earth's surface.
Hope this helped you!
[9]
(b) A billiard ball B at rest is struck by an identical ball A moving with a speed of 10 m/s along
the positive y-axis. After the collision, the two balls move off in directions that are perpendicular
to each other, with ball A making 15° with the positive y-axis. Find the final velocities (Direction
and magnitude) of both balls. [16]
Answer:
9.66 m/s 15° with +y
2.59 m/s 75° with +y
Explanation:
Momentum is conserved in the y direction.
mu₁ + mu₂ = mv₁ + mv₂
u₁ + u₂ = v₁ + v₂
10 m/s + 0 m/s = v₁ cos 15° + v₂ cos 75°
10 = v₁ cos 15° + v₂ cos 75°
Momentum is conserved in the x direction.
mu₁ + mu₂ = mv₁ + mv₂
u₁ + u₂ = v₁ + v₂
0 m/s + 0 m/s = v₁ sin 15° − v₂ sin 75°
0 = v₁ sin 15° − v₂ sin 75°
v₁ sin 15° = v₂ sin 75°
v₂ = v₁ sin 15° / sin 75°
Substitute.
10 = v₁ cos 15° + (v₁ sin 15° / sin 75°) cos 75°
10 = v₁ cos 15° + v₁ sin 15° / tan 75°
10 = v₁ (cos 15° + sin 15° / tan 75°)
v₁ ≈ 9.66 m/s
v₂ ≈ 2.59 m/s
Estimate the number of dollar bills (15.5 cm wide), placed end to end, that it would take to circle the Earth (radius = 6.40 × 103 km).
Answer:
#_bills = 2.59 10⁸ Bills
Explanation:
For this exercise we must calculate the length of the Earth's circle
L = 2π r
Let's reduce to the SI system
r = 6.40 10³ km (1000m / 1km) = 6.40 10⁶ m
d = 15.5 cm (1m / 100cm) = 0.155 m
L = 2π 6.40 10⁶
L = 40.21 10⁶ m
now we can use a direct rule of proportions (rule of three). If 1 bill has d = 0.155, how much bill will have L
#_bills = 1 L / d
#_bills = 1 40.21 10⁶6 / 0.155
#_bills = 2.59 10⁸ Bills
the total number of bills is 2.6 10⁸ bills
17
The diagram below shows an ideal transformer which is supplied with an
alternating voitage of 240V and a current of 1A.
If the secondary current is 5A, what is the secondary voltage?
A
1400V
B
1200V
C
240V
D48V
Answer:
I think the answer is B, I am not for sure
There are three long parallel wires arranged so that, in cross-section, they occupy the points of an equilateral triangle. Is there any way to arrange the currents so that all three wires attract each other?
Answer:
Yes, there is such a way.
Explanation:
If currents flow in the same direction in two or more long parallel wires, there will be an attractive force between the wires. If the current flows in different directions, there will be a repulsive force between the wires. In this case, these three parallel wires, can be be made to carry current in the same direction, creating an attractive force between all three wires.
Note that it is not possible to have at the least one of them carry current in the opposite direction and still have an attractive current between them.
do amps in circuit change if something is removed from the circuit for example:
There is two lamps in a circuit if one is removed would the current in the circuit change
Answer:
Yes, the current will change if one light bulb is removed from the circuit.
Explanation:
Recall that each light bulb possess in fact resistance, and electric energy is converted into light and heat as current circulates through each. therefore, removing one light bulb will change the total resistance of the circuit , thus affecting the current through it according to Ohm's Law.
a planet of mass 2*10^24 kg is at location <2*10^11,-4*10^11,0>m. A star of mass 5*10^30 kg is at location <-5*10^11,6*10^11,0>m. The planet is in a circular orbit around the star, moving at a constant speed. What is the gravitational force vector on the planet due to the star
Answer:
(-2.57*10^20, 3.67*10^20, 0)
Explanation:
Refer to the attachment.
I hope that helps
IV) Fill in the blanks:
1) Equal volumes of different substances have
masses.
2) The more closely packed arrangement the particles of a substance have,
its density.
3) SI unit of power is
4) An iron nail sinks in water but can float on
5) Balloons used for advertisements are filled with_gas.
6)
is the primary mode of heat transfer in liquid and gases.
1.) equal volume of different substances have "different" masses.
2.)The more closely packed arrangement the particles of a substance have, "increases" its density.
3.)the SI unit of power is "Watts".
4.)an iron nail sinks in water but floats on " mercury ".
5.)balloons used for advertisements are filled with " helium" gas.
6.)"Conduction" is the primary mode of heat transfer in liquid and gases.
I hope this helps you...
Which statements describe what is occurring at t=5 seconds? Check all that apply
Answer: The object changed directions
The object sped up
Explanation:
A construction worker 40.0 m above the ground drops his hammer. How long does his shouted warning take to reach the ground if the speed of sound under these conditions is 335 m/s?
Answer:
0.239secondsExplanation:
Using the formula for calculating the distance between the worker (source) and the reflector (ground) expressed as shown:
2x = vt where:
x is the distance between the source and the reflector
v is the velocity of sound in air
t is the time taken by is shout warning to reach the ground
Given parameters
x = 40.0m
v = 335m/s
Required
The time taken by is shout warning to reach the ground
Using the formula 2x = vt
t = 2x/v
t = 2(40)/335
t = 80/335
t = 0.239seconds
Hence it will take 0.339 seconds for his shout warning to reach the ground