Answer:
Critical angle is a angle of incidence, for which refraction is 90 degree, this is a least angle of incidence at which total reflection takes place, please mark me Brainliest
electric field due to on the surface of the charge sphere
Explanation:
static electricity draws energy
An Olympic skier glides down a hill, inclined at 25° to the horizontal, at 18 m/s.
How long did it take for her to ski 800 m to the bottom of the hill?
44.4 s
10.5 s
4.0 s
1.6 s
Divide total meters by meters per second:
800 m / 18 m/s = 44.4 seconds
Answer: 44.4
The tires of a car make 77 revolutions as the car reduces its speed uniformly from 95.0 km/h to 65.0 km/h. The tires have a diameter of 0.90 m.
If the car continues to decelerate at this rate, how far does it go? Find the total distance.
Answer:
Explanation:
95.0 km/hr = 26.39 m/s
65 km/hr = 18.06 m/s
Circumference of a tire is 0.9π m
77 revolutions is a distance of
77(0.9π) = 69.3π m
v² = u² + 2as
a = (v² - u²) / 2s
a = (18.06² - 26.39²) / (2(69.3π))
a = -0.85 m/s²
s = (v² - u²) / 2a
s = (0² - 26.39²) / 2(-0.85)
s = 409 m
What is the angle θ between vectors A⃗ and B⃗ if A⃗ =4ı^−4ȷ^ and B⃗ =−5ı^+7ȷ^?
The characteristics of the scalar product allows to find the angle between the two vectors is:
The angle θ = 170º
The scalar product is the product between two vectors whose result is a scalar.
A . B = |A| |B| cos θ
Where A and B are the vectors, |A| and |B| are the modules of the vectors and θ at the angle between them.
The vector is given in Cartesian coordinates and the unit vectors in these coordinates are perpendicular.
i.i = j.j = 1
i.j = 0
A . B = (4 i - 4j). * -5 i + 7j)
A . B = - 4 5 - 4 7
A. B = -48
We look for the modulus of each vector.
|A| = [tex]\sqrt{x^2 +y^2 }[/tex]
|A| = [tex]\sqrt{4^2 + 4^2}[/tex]
|A| = 4 √2
|B| = [tex]\sqrt{5^2 +7^2}[/tex]
|B| = 8.60
We substitute.
-48 = 4√2 8.60 cos θ
-48 = 48.66 cos θ
θ = cos⁻¹ [tex]\frac{-48}{48.664}[/tex]
θ = 170º
In conclusion using the dot product we can find the angle between the two vectors is:
the angle θ = 170º
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You have a 25 W and a 100 W bulb at home. When you connect one or the other, which bulb carries the greater current
Answer:
100 w bulb has more current.
Explanation:
P=V^2/R.
when velocity is constant power is inversly proportional to resistence, so 25 W will have an hogher resistance tjan a 100 w bulb.
P=VI
when v is constant, power is directly proportional to I. hence, 100 w bulbs will carry more current.
When you connect one or the other, the bulb that's connected carries more current than the one that's not connected.
When you connect BOTH of them, the 100W bulb carries more current than the 25W one.
URGENTLY NEED HELP!!!!!!
the stretch of a spring and the force it exerts are inversely proportional.
Select one:
O True
O False
Answer:
False.
Explanation:
Pls help me with this one :))
Answer:
Row A is correct
Explanation:
both conduction and convection require mass to complete any heat transfer. A vacuum contains no mass
determine the total current on the circuit bellow
Answer:
170/179 A ≈ 949.7 mA
Explanation:
Finding equivalent impedance of a bridge network can be simplified by converting one end of it from a Δ to a Y configuration. The equivalent resistance in the Y connection is the product of the two resistors connected to that node, divided by the sum of all three resistors.
Considering the left side of the top two branches, the equivalent Y network values are ...
(10)(15)/(10+15+25) = 150/50 = 3 . . . ohms
connected to the right-end node
(25)(10)/50 = 5 . . . ohms
connected to the top-center node, and ...
(25)(15)/50 = 7.5 . . . ohms
connected to the center node of the middle branch.
__
Then the top two branches of this circuit have an equivalent impedance equal to 3 ohms in series with the parallel combination of (5+20) ohms and (7.5+10) ohms. That value is ...
3 + (25)(17.5)/(25 +17.5) = 226/27 ≈ 13.294 . . . ohms
This, in turn, is in series with the 2.5 ohms in the bottom branch, bringing the total circuit resistance to about 15.794 ohms, or 537/34 ohms.
The total source current is then ...
I = V/R = (15 v)/(537/34 Ω) = 170/179 A ≈ 0.9497 A
_____
Alternate solutions
Alternatively, you can write and solve three node or loop equations for this circuit. For example, the equations for CCW loop currents, with I1 as the bottom loop, could be written in augmented matrix form as ...
[tex]\left[\begin{array}{ccc|c}27.5&-10&-15&-15\\-10&55&-25&0\\-15&-25&50&0\end{array}\right][/tex]
The result is the same.
A phone is dropped from the roof of the school building. The building is 13.2 meters high. How long was the phone in the air before it crashed on the ground?
Answer:
5scs
Explanation:
phones fall fast so i guessed
Give four characteristics of forces.
Answer:
Force has both magnitude and direction.More than one force can be applied on an object.Forces applied in the same direction add up to each other.It may change the shape of an object.Explanation:
Hope it helps you!!Explanation:
Characteristics of Force:
Forces are due to an interaction of at least two objects. It may change the state of motion of an object. It may change the shape of an object. Forces applied on an object in the same direction add to one another and the resultant is in the same direction.
A rod of length 0.82 m, rotating with an angular speed, 4.2 rad/s, about axes that pass perpendicularly through one end, has a mass of 0.63 kg, which is distributed uniformly along its length. Find the kinetic energies of the rod.
Answer:
Explanation:
KE = ½Iω²
ΚΕ = ½(mL²/3)ω²
ΚΕ = ½(0.63(0.82²)/3)4.2²
ΚΕ = 1.24541928
KE = 1.2 J
a mass of 7.5kg has a weight of 30n on a certain planet calculate the acceleration due to gravitt on this planet
Answer:
Acceleration due to gravity on a certain planet = 4 m/s²
Explanation:
According to the question,
Weight = 30 N
Mass = 7.5 kg
Let acceleration due to gravity be 'a'
Formula:
Weight = Mass × Acceleration due to gravity
30 = 7.5 × a
a = 30/7.5
a = 4 m/s²
A car C moving with a speed of 65 km/h on a straight road is ahead of motorcycle M moving with the speed of 80 km/h in the same direction. What is the velocity of M relative to A?
Answer:
The answer is 15. Step by step is you times 80 by 65 and then you divided by 2 and you call your teacher
2- Calculate the momentum of cruise liner of mass 20 000 tones when it is travelling at 6.0ms-1
(1 tonne = 1000kg). Note: tonne
Answer:
P = 120,000,000
Explanation:
P = m.v
m = (20,000.1000)= 20,000,000kg
v = 0.6 m/s
p = (20,000,000)(0.6)
p = 120,000,000 kg⋅m/s
Given the force diagram of the basketball, what can you tell about the basketball motion?
Newton's laws allow to find the result for the movement of the basketballl:
On the vertical axis the ball is on the ground. On the horizontal axis the ball is accelerating in the direction of the pushing force.
Newton's laws establish the relationship between the forces on objects:
The 1st law states that if the net force is zero the object is stationary or with constant speed. The 2nd law gives a relation of the force with the mass and the acceleration of the body. The 3rd. Law states that the force appears in pairs, one on each body with the same magnitude, but in the opposite direction.
Let's apply these principles to the ball's motion diagram.
The two vertical forces are in the opposite direction, one is due to the weight of the body and the other is the attraction of the earth to the support of the ball, they are of equal magnitude, not their action-reaction force and reluctant because it is applied to the same body
In conclusion we can say that the ball is on the ground.
The two horizontal forces are in the opposite direction, the thrust force is greater than the friction therefore using Newton's second law the ball must be accelerating in the direction of the thrust force.
In conclusion we can say that the ball is accelerating in the direction of the pushing force.
In conclusion using Newton's laws we can find the result for the motion of the basketball:
On the vertical axis the ball is on the ground. On the horizontal axis the ball is accelerating in the direction of the pushing force.
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A cylindrical region of radius R contains a uniform magnetic field parallel to its axis. The field is zero outside the cylinder. If the magnitude of the field is changing at the rate dB/dt, the electric field induced at a point 2R from the cylinder axis is:
The magnitude of the induced electric field is (RdB/dt)/4
The induced electric field is gotten from
-∫E.dl = dФ/dt where E = induced electric field, dl = path length vector, Ф = magnetic flux through cylindrical region = AB where A = area of magnetic flux = πR² where R = radius of cylindrical region and B = magnetic field.
So, -∫E.dl = dФ/dt
-∫E.dl = dAB/dt
-∫Edlcos0 = AdB/dt (where E.dl = Edlcos0 = Edl since E and dl are parallel to each other.)
So -∫Edl = πR²dB/dt
-E∫dl = πR²dB/dt (∫dl = 2πr since the integral is the circumference of the path)
-E(2πr) = πR²dB/dt (we integrate dl from r = 0 to 2R)
-E2π(2R - 0) = πR²dB/dt
-E4πR= πR²dB/dt
E = πR²dB/dt ÷ 4πR
E = -(RdB/dt)/4
So, the magnitude of the induced electric field is (RdB/dt)/4
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(a) What frequency is received by a person watching an oncoming ambulance moving at 105 km/h and emitting a steady 853 Hz sound from its siren
Answer:
(a) f' = 878 Hz
(b) f' = 735 Hz
Explanation:
Which processes result in the release of carbon? Select three options.
Animals break down food molecules to obtain energy.
The remains of producers are broken down by decomposers.
The remains of consumers are broken down by soil decomposers.
Producers take in carbon dioxide.
Producers make sugars and starches.
Answer:
The remains of producers are broken down by decomposers.
The remains of consumers are broken down by soil decomposers.
Animals break down food molecules to obtain energy.
Explanation:
Answer:
It is A. B. and C.
Explanation:
Hope this helps
Which is the best way to avoid plagiarism? O use more than one source from your research O repeat information from your sources O present a topic in your own words O understand your topic before you begin writing
Answer:
O present a topic in your own words
Explanation:
Plagiarism is using someone else's words or work without giving them proper credit. Presenting a topic in your own words means you are not copying anyone.
Answer:
present a topic in your own words
Explanation:
3. What can you infer about the position of the galaxies 100 million years before this telescope photo was taken
The galaxies are in constant motion so it can be inferred that their position will not be the same as a hundred million years ago.
A galaxy is a term to refer to the set of stars, gas clouds, planets, cosmic dust, dark matter, and energy gravitationally united in a more or less defined structure in the universe.
Galaxies are in constant motion because the elements that make them up are not static at any time; The galaxies rotate around the center of the galaxy. If they were still, the gravitational attraction would cause them to immediately fall towards the center of the galaxy: it is the same that would happen to the Earth and the other planets if they stopped rotating around the Sun, they would fall towards the Sun.
According to the above, it can be inferred that the galaxies after a while have moved from the place where they were last seen.
Note: This question is incomplete because there is some missing information. However, I can answer based on my general prior knowledge.
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What's the kinetic energy of an object that has a mass of 12 kilograms and moves with a velocity of 10 m/s?
Answer:
600 JExplanation:
Given,
Mass (m) = 12 kgVelocity (v) = 10 m/sAs we know,
Kinetic Energy,
[tex] E_{k} \: = \frac{1}{2} m {v}^{2} [/tex]Therefore ,
Kinetic energy of the object is,
[tex] = \frac{1}{2} \times 12 \: kg \times 10 \: m {s}^{ - 1} \times 10 \: m {s}^{ - 1} [/tex]
(On dividing 12 by 2 we get 6)= (6 × 10 × 10) J [As 'J' stands for 'joule']
= 600 J (Ans)
Short, difficult activities that push your body are called
A.
aerobic activity
B.
anaerobic activity
C.
muscle strength
D.
exercise
Answer:
B. is your answer
Explanation:
Have a good day
Sincerly, lipor
Short, difficult activities that push your body are called anaerobic activities. Option b is correct
They are high-intensity exercises that do not require oxygen and primarily use stored energy sources within the muscles. Examples include weightlifting or sprinting.
Short, difficult activities that push your body are called anaerobic activity. Anaerobic activities are high-intensity exercises that do not require oxygen and primarily use stored energy sources within the muscles, such as weightlifting or sprinting. These activities help build muscle strength and improve power and speed.
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WILL MARK BRAINLIEST
1. What is the difference between distance and displacement?
A. Distance is measured in feet. Displacement is measured in meters
B. Distance is the difference between how quickly you move between two points. Displacement is the average of that motion
C. Distance is a measure of length of travel. Displacement is the measure of the time it takes to move that length
D. Distance is the length of travel. Displacement is the straight line distance between the starting point and the ending point
2. When forces are in opposite directions, they subtract from one another
A. True
B. False
3. When two forces are in opposite directions, and they are the exact same magnitude, the forces will
A. Subtract from each other
B. Cancel Out
C. Go on Infinitely
D. eventually reach equilibrium
4. Acceleration is a change in motion over time
True or False
Answer:
1. C
2. True
3. D
4. True
Explanation:
While distance refers to “how much land an object has traversed throughout its journey,” displacement measures “how far an object is out of place.” In this post, let's look at the difference between distance and displacement. Thus, option C is correct.
What are the distance and displacement?Displacement and distance are two distinct ideas. The total distance travelled is larger than the displacement between those two points if an object changes direction while travelling.
Distance is the length of any path connecting any two places. Displacement is the straight-line distance between any two points when calculated along the shortest route.
Therefore, The direction is ignored when calculating distance. The direction is accounted for in the displacement calculation.
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2. Jason rode his bike 10 miles and only rode for 2 hours how fast was he going?
Answer:
5 miles per hour.
Explanation:
10miles / 2hours = 5 mph
PLZ HURRY
When you hold a racquet and swing your arm toward the ball, there are two kinds of resistance working against your muscles—the ______ and the ______.
A.
racket, air
B.
air, ball
C.
ball, net
D.
air, racket
Answer:
It should just be A
Explanation:
I dont see the difference between these 2 but ill choose A and update you
Answer:
A: racket, air
Explanation:
A 30.0-g object moving to the right at 20.5 cm/s overtakes and collides elastically with a 13.0-g object moving in the same direction at 15.0 cm/s. Find the velocity of each object after the collision. (Take the positive direction to be to the right. Indicate the direction with the sign of your answer.)
Let m₁ and m₂ be the masses of the two objects, and v₁ and v₂ their initial velocities. So
m₁ = 30.0 g = 0.0300 kg
m₂ = 13.0 g = 0.0130 kg
v₁ = + 20.5 cm/s = 0.205 m/s
v₂ = + 15.0 cm/s = 0.150 m/s
and we want to find v₁' and v₂', the final velocities of either object after their collision.
Momentum is conserved throughout the objects' collision, so that
m₁v₁ + m₂v₂ = m₁v₁' + m₂v₂'
where v₁' and v₂' are the first and second object's velocities after the collision.
Kinetic energy is also conserved, so that
1/2 m₁v₁² + 1/2 m₂v₂² = 1/2 m₁(v₁')² + 1/2 m₂(v₂')²
or
m₁v₁² + m₂v₂² = m₁(v₁')² + m₂(v₂')²
From the first equation (omitting units), we have
0.0300 • 0.205 + 0.0130 • 0.150 = 0.0300 v₁' + 0.0130 v₂'
0.0810 = 0.0300 v₁' + 0.0130 v₂'
81 = 30 v₁' + 13 v₂'
From the second equation,
0.0300 • 0.205² + 0.0130 • 0.150² = 0.0300 (v₁')² + 0.0130 (v₂')²
0.00155 ≈ 0.0300 (v₁')² + 0.0130 (v₂')²
1.55 ≈ 30 (v₁')² + 13 (v₂')²
Solving both equations simultaneously gives two solutions, one of which corresponds to the initial conditions. The other yields
v₁' ≈ + 0.172 m/s
and
v₂' ≈ + 0.227 m/s
Heat is transferred from molecules with more kinetic energy to molecules with _________kinetic energy.
Answer:
less
Explanation:
heat travels from hotter to colder object. hotter object has more kinetic energy.
A pumpkin is shot upwards at a speed of 15.5 m/s from the ground and lands on a 3.00m
high platform. How long before it hits and smashes?
Answer:
0.2seconds
Explanation:
Speed=distance/time
15.5m/s=3.00m/x seconds
x=3/15.5
x=0.1935
x=0.2sec
hope this helped
5 What is the maximum speed at which a car round a curve of 25m radius on a level road if the coefficient of static friction between the tires and the road is 0.80?
Hi there!
On a level road:
∑F = Ff (Force due to friction)
The net force is the centripetal force, so:
mv²/r = Ff
Rewrite the force due to friction:
mv²/r = μmg
Cancel out the mass:
v²/r = μg
Solve for v:
v = √rμg
v = √(25)(9.81)(0.8) = 14.01 m/s
If work stays the same and the distance is increased, then less force is needed to do the work.
True
False
Answer:
False
Explanation:
This is because the work is the same so the force won't change