Answer:
EMF = 11.35 V
R = 0.031Ω
Explanation:
To find the battery's EMF and the internal resistance we need to use Ohm's law:
[tex] V = IR [/tex]
Where:
V: is the voltage
I: is the current
R is the resistance
We have:
The current through the battery is 64.2 A and the potential difference across the battery terminals is 9.36 V:
[tex] \epsilon = V + IR [/tex]
[tex] \epsilon = 9.36 V + 64.2A*R [/tex] (1)
When only the car's lights are used, the current through the battery is 1.96 A and the terminal potential difference is 11.3 V:
[tex] \epsilon = 11.3 V + 1.96A*R [/tex] (2)
By solving equation (1) and (2) for R we have:
[tex] 9.36 V + 64.2A*R = 11.3 V + 1.96A*R [/tex]
[tex]R = \frac{1.94 V}{62.24A} = 0.031 \Omega[/tex]
Hence, the internal resistance is 0.031 Ω.
Now, by entering R into equation (1) we can find the battery's EMF:
[tex]\epsilon = 9.36 V + 64.2A*0.031 \Omega[/tex]
[tex] \epsilon = 11.35 V [/tex]
Therefore, the battery's EMF is 11.35 V.
I hope it helps you!
A motorcyclist goes around an un-banked (i.e., flat) circular turn of radius 31m, at a constant speed of 110km/hr (convert this to m/s). What is the minimum coefficient of static friction needed to keep the tires from slipping? Explain why the answer is (or is not) plausible.
Answer:
[tex]\mu_{s} = 3.071[/tex]
This result represents an absurd, not plausible, as coefficient of frictions from materials have values between 0 and 1.
Explanation:
From Second Newton's Law we understand that centripetal acceleration experimented by motocyclist is due to force derived from static friction. And normal force of the ground on motocyclist equals weight of motocyclist due to the flatness of circular turn. The equations of equilibrium of the motocyclist is:
[tex]\Sigma F_{x} = \mu_{s}\cdot N = m\cdot \frac{v^{2}}{R}[/tex] (Eq. 1)
[tex]\Sigma F_{y} = N-m\cdot g = 0[/tex] (Eq. 2)
Where:
[tex]\mu_{s}[/tex] - Static coefficient of friction, dimensionless.
[tex]N[/tex] - Normal force, measured in newtons.
[tex]m[/tex] - Mass of the motocyclist, measured in kilograms.
[tex]g[/tex] - Gravitational acceleration, measured in meters per square second.
[tex]v[/tex] - Speed of the motorcyclist, measured in meters per second.
[tex]R[/tex] - Radius of the circular turn, measured in meters.
The static coefficient of friction is cleared in (Eq. 1):
[tex]\mu_{s} = \frac{m\cdot v^{2}}{N\cdot R}[/tex]
From (Eq. 2) we get that normai force is:
[tex]N = m\cdot g[/tex]
And we expand the resulting expression in (Eq. 1):
[tex]\mu_{s} = \frac{m\cdot v^{2}}{m\cdot g\cdot R}[/tex]
[tex]\mu_{s} = \frac{v^{2}}{g\cdot R}[/tex] (Eq. 3)
If we know that [tex]v = 30.556\,\frac{m}{s}[/tex], [tex]g = 9.807\,\frac{m}{s^{2}}[/tex] and [tex]R = 31\,m[/tex], the expected static coefficient of friction is:
[tex]\mu_{s} = \frac{\left(30.556\,\frac{m}{s} \right)^{2}}{\left(9.807\,\frac{m}{s^{2}} \right)\cdot (31\,m)}[/tex]
[tex]\mu_{s} = 3.071[/tex]
This result represents an absurd, not plausible, as coefficient of frictions from materials have values between 0 and 1.
A toy rocket is launched vertically from ground level (y = 0 m), at time t = 0.0 s. The rocket engine provides constant upward acceleration during the burn phase. At the instant of engine burnout, the rocket has risen to 98 m and acquired a velocity of The rocket continues to rise in unpowered flight, reaches maximum height, and falls back to the ground. The upward acceleration of the rocket during the burn phase is closest to:
29 m/s2
31 m/s2
33 m/s2
30 m/s2
32 m/s2
Explanation:
The question is incomplete. Here is the complete question.
A toy rocket is launched vertically from ground level (y = 0 m), at time t = 0.0 s. The rocket engine provides constant upward acceleration during the burn phase. At the instant of engine burnout, the rocket has risen to 98 m and acquired a velocity of 30m/s. The rocket continues to rise in unpowered flight, reaches maximum height, and falls back to the ground. The upward acceleration of the rocket during the burn phase is closest to...
Given
initial velocity of rocket u = 0m/s
final velocity of rocket = 30m/s
Height reached by the rocket = 98m
Required
upward acceleration of the rocket
Using the equation of motion below to get the acceleration a:
[tex]v^2 = u^2+2as\\30^2 = 0^2 + 2(a)(98)\\900 = 196a\\a = \frac{900}{196}\\a = 4.59m/s^2[/tex]
Hence upward acceleration of the rocket during the burn phase is closest to 5m/s²
Note that the velocity used in calculation was assumed.
I'm imagining a scene in a future Pirates of the Carribean movie. The Black Pearl tried to surf a wave to get over a sandbar and didn't quite make it. The stern (back end) of the ship is stuck on the sand bar and is a sitting duck for the Royal Navy ships following her. The Black Pearl has 2 cannons pointed forward (bowchasers) and 3 cannon pointing backward (sternchasers). Which cannons should Captain Jack Sparrow fire to move his ship forward off the sand bar?
To the left (port)
To the right (starboard)
To the back (the sternchasers)
To the front (the bowchasers)
Answer:
3 in the back so it can shove it off the sand bar
Explanation:
How is the average American diet affected by our current food system?"
A cat chases a mouse for a distance of 9.0 m over 16 s before getting tired. What is the cats average speed?
Answer:
The answer is 0.56 m/sExplanation:
The speed of the cat can be found by using the formula
[tex]v = \frac{d}{t} \\ [/tex]
d is the distance
t is the time taken
From the question we have
[tex]v = \frac{9}{16} = \\ = 0.5625[/tex]
We have the final answer as
0.56 m/sHope this helps you
ionic bonds form when electrons?
Answer:
when the electron transferred permanently to another atom
Metals that have shine and luster?
Answer:
luster
Explanation:
A 126 N force is applied at an angle of 25.00 to a 8.50 kg block pressed against a rough vertical wall and the block slides down the wall at constant velocity. Calculate the coefficient of kinetic friction between the block and the wall.
Answer:
μk = 0.58
Explanation:
If the block is sliding down at constant speed, this means that no net force is acting upon it in the vertical direction.As the block is pressed on the wall, this means that it doesnt accelerate in the horizontal direction either, so no net force acts upon it in this direction also.In this direction, we have only two forces acting, equal and opposite each other, one is the normal force (exerted by the wall) and the other is the horizontal component of the applied force.If the applied force forms an angle of 25º with the wall (which is vertical), this means that we can get its projection along the horizontal direction, using simple trigonometry , as follows:[tex]F_{apph} = F_{app} * sin\theta = 126 N * sin 25 = 53.3 N[/tex]
⇒ [tex]F_{n} = - F_{apph} = -53.3 N[/tex]
In the vertical direction, we have three forces acting on the block: the weight pointing downward, the kinetic friction force (as we know that the block is sliding), and the vertical component of the applied force, in the same direction as the friction one.As we have already said, the sum of these forces must be 0.[tex]F_{g} + F_{appv} + F_{ff} = 0 (1)[/tex] where Fg is the weight of the block, Fappv is the vertical component of the applied force, and Fff is the kinetic friction force.Replacing these forces by their mathematical expressions, we have:[tex]F_{g} = m_{b} * g = 8.5 Kg * (-9.8 m/s2) = -83.3 N[/tex]
[tex]F_{appv} = F_{app}* cos\theta = 126 N * cos 25 = 114.2 N[/tex]
[tex]F_{ff} = \mu_{k}* F_{n} =\mu_{k} * (-53.3 N)[/tex]
Replacing in (1), and solving for μk, we finally get:μk = 0.58
Wind eroding the rocks on a moutain is an example of the atmosphere interacting with the cryosphere
true or false
Answer:
False
Explanation:
The cryosphere is all the part of the earth where water is in solid form. Where wind interacts with rocks, it is an example of atmosphere - geosphere interaction.
Rocks are part of the geosphere The geosphere is the part of the earth made up of solid rocks. Wind erosion occurs when wind wears down part of the geosphere.A block of a plastic material floats in water with 35.6% of its volume under water. What is the density of the block in kg/m3
Answer:
The density is [tex]\rho_{block} = 356 \ kg/m^3 [/tex]
Explanation:
From the question we are told that
The proportion of the plastic under water is p = 0.356
Generally at equilibrium the buoyant force is equal to the weight of the block i.e
[tex]B = mg[/tex]
Generally the Buoyant force is mathematically represented as
[tex]B = \rho * V * g[/tex]
Here [tex]\rho[/tex] density of the water with value
[tex]\rho = 1000 kg/m^3[/tex] ,
V is the volume of water displaced by the block which is [tex] p * V_{block [/tex] ,
So
[tex]1000 * 0.356 V_{block} * g = m * g[/tex]
Here m is the mass of the block which is mathematically represented as
[tex]m = \rho_{block} * V_{block}[/tex]
So
[tex]1000 * 0.356 V_{block} * g = \rho_{block} * V_{block}* g[/tex]
[tex]1000 * 0.356 V_{block} = \rho_{block} * V_{block}* g[/tex]
=> [tex]\rho_{block} = 1000 * 0.356[/tex]
=> [tex]\rho_{block} = 356 \ kg/m^3 [/tex]
1. A car travels 36 miles North and then 45 miles East. How far does it
displace?
2. Jason walks 100 meters South and 500 meters West. How far does he
displace from his starting point?
3. If a person riding a back rides 60 meters West then 40 meters North, how far
have they displaced?
4. What is the displacement of a car that travels 700 miles North and then 500
miles East?
5. If a car travels from it's driveway to a town 300 miles North, then returns to
its driveway, how far has it displaced?
6. Does a car displace if it travels 200 miles North and then 100 miles South? If
so, how far?
7. If a car travels South for 650 km and then East for 650 km, how far has it
displaced?
8. Does a racecar displace around a circular track from the start to the end of
the race?
Needs y’all’s help answering these 8 questions please
Answer:
Explanation:
Displacement is the shortest distance or path between two points.
1) Displacement = √(36² + 45²) = 57.63 miles
2) Displacement = √(100² + 500²) = 509.9 meters
3) Displacement = √(60² + 40²) = 72.11 miles
4) Displacement = √(700² + 500²) = 860.23 miles
5) Displacement = 300 - 300 = 0 miles
6) Displacement = 200 + 100 = 300 miles
7) Displacement = √(650² + 650²) = 919.24 miles
8) Yes, since a distance is moved in a direction
Sophia pushes with a 40-N horizontal force on a 4.0-kg box resting on a lab bench. The box slides against a horizontal friction force of 24 N. show that the box acceleration at 4.0 m/s2
Answer:
a = 4.0 m / s², so the result of the exercise is correct
Explanation:
This is an exercise on Newton's Second Law
F = m a
we create a reference system with the horizontal x axis and the vertical y axis
Axis y
N -W = 0
X axis
F -fr = m a
give us the applied force F = 40 N, the value of the friction outside fr = 24 N
a = (F - fr) / m
let's calculate
a = (40 - 24) / 4
a = 4.0 m / s²
so the result of the exercise is correct
On cold winter mornings, Ellen's mother will frequently put a space heater in the kitchen. The space heater has coils that use electrical energy to make heat. When the heater is turned on, the coils glow bright orange and heat the room. What types of energy are given off by the space heater?
Answer:
C
Explanation:
It seems right.
answer
Think of it this way. Osmosis occurs when water flows to a different side given its a membrane or not. This is because it flows to a less dense area to reach equilibrium between the two sides. Heat is very similar. It will try to spread to places where there is not as much heat. Keeping the laws of heat travels up, the heat from the coils will reach the ends. We call this "Thermal Equilibrium"
use the hubble's law to determine the distance to a quasar receding at 75% the speed of light. The speed of light is 300,000 km/sec. assume Hubble's constant is
Complete question:
use the hubble's law to determine the distance to a quasar receding at 75% the speed of light. The speed of light is 300,000 km/sec. assume Hubble's constant is 2.2 x 10⁻⁵ km/s/Lyr
Answer:
The distance to the quasar is 1.02 x 10¹⁰ Lyr
Explanation:
Given;
speed of light, v = 300, 000 km/sec
Hubble's constant, H₀ = 2.2 x 10⁻⁵ km/s/Lyr
percentage of the quasar recession = 75% of speed of light
Hubble's Law is given by;
[tex]v =H_od\\\\d = \frac{v}{H_o}\\\\d= \frac{(0.75*300,000)}{2.2*10^{-5}}.Lyr\\\\d = 1.02*10^{10} \ Lyr[/tex]
Therefore, the distance to the quasar is 1.02 x 10¹⁰ Lyr
An 80-kg bungee jumper jumps off a bridge. Rubber bungee cords act as a large spring attaching the jumper to the bridge. A bear standing in the river below catches the jumper. If the spring constant of the bungees is 20 N/m and they stretch 50 m. How much force must the bear apply to keep the jumper from moving?
Answer:
The force is [tex]F_b = 216 \ N [/tex]
Explanation:
From the question we are told that
The mass of the bungee jumper is m = 80 kg
The spring constant is [tex]k = 20 \ N/ m[/tex]
The extension of the rubber bungee cords is x = 50 m
Generally the weight of the jumper is
[tex]W = m * g[/tex]
=> [tex]W = 80 * 9.8 [/tex]
=> tex]W = 784 \ N [/tex]
Generally the returning force of the rubber bungee cords is mathematically represented as
[tex]F = k * x[/tex]
=> [tex]F = 20 * 50 [/tex]
=> [tex]F = 1000 \ N [/tex]
The force to be applied by the bear is
[tex]F_b = F - W[/tex]
=> [tex]F_b = 100 - 784[/tex]
=> [tex]F_b = 216 \ N [/tex]
help me get the answer in Physical Science.
Answer:
lithium
Explanation:
I took physical science 2 years ago and passed with an A
What is the cause of space
Answer:
this depends on religion
Explanation:
some people believe in the big bang and some people believe in Jesus Christ and other gods.
big bang- Gravity
God- spoke
If you are driving to see your cousins at a speed of 84.6 km/h and it took you 6.5 h to get there, how far did you travel?
Answer: 549.9 km
Explanation: 84.6km every hour so 84.6*6.5= 549.9
Donald Duck Matthews wanted to show up all his friends with his newfound dancing skills he left his house to go to dressers house 20 m north from where he was he's so dresser his moves went off to the next place and next stop was 10 m west at choirboys house luckily he saw Eddie there too. After showing off his skills agai he was satisfied, but he still had to show one last person up. His brother who was 15 m South. After making it there he showed hos moves and smiled. what was Ducks displacement?
A. 12 m SW
B. 11 m NW
C. 45 m NW
D. 45 m NE
The final displacement of the duck would be 11.18 meters in NW, therefore the correct answer is option B.
What is displacementDisplacement describes this shift in location.
As given in the problem Donald Duck Matthews wanted to show up all his friends with the newfound dancing skills he left his house to go to dressers house 20 m north from where he was he's so dresser his moves went off to the next place and next stop was 10 m west at choirboys house luckily he saw Eddie there too.
After showing off his skills again he was satisfied, but he still had to show one last person up. His brother was 15 m South.
His final position would be 5 meters north and 10 meters west.
The displacement of the Duck = √( 10² + 5²)
= 11.18 meters in NW
Thus, the final displacement of the duck would be 11.18 meters in NW.
To learn more about displacement here, refer to the link;
brainly.com/question/10919017
#SPJ2
Plz help me fast WITH EXTRA POINTS AFTER SUBMITTING
Answer:
4 bobux
Explanation:
one bobux
two bobux
three bobux
four bobux
2 forces are acting on a body. I forgot the body doesn't it's position or shape, the forces.......a)must be of equal magnitude b)must be parallel and opposite c)must add upto zero d)must be in a single line
Answer:
C
Explanation:
only if there is a net force of zero, the body will not move
some people may say B but that is wrong because maybe one force is greater than the other so the object would still move even though the forces are in opposite directions and parallel
Two students measured the length of the same stick, each using a different 30 cm ruler. One student reported a length of 22 cm, and the other reported a length of 8 cm. The most likely explanation for the difference in the reported values is that one —
A. *student improperly read the ruler
B. ruler was metal and the other ruler was plastic
C. student viewed the ruler from a different angle
D. ruler was constructed with nonstandard cm marks
Answer:
C. student viewed the ruler from a different angle
Explanation:
It is the problem of viewing the scale from different sides or angles. If we assume the actual length of the stick to be 22 cm. Then the first student measured the length by reading the values from 1 cm towards 22 cm on the scale. While, the second student measured the length of the stick by reading the values from the other side or the other angle of the scale, that is, from 30 cm mark towards 1 cm. And in that case the the length of the 22 cm long stick will appear as:
30 cm - 22 cm = 8 cm
Therefore, the second student read 8 cm on scale. So, the correct option is:
C. student viewed the ruler from a different angle
A 7.4 A current is set up in a circuit for 7.8 min by a rechargeable battery with a 3.0 V emf. By how much is the chemical energy of the battery reduced?
Answer:
10389.6 J
Explanation:
Power is the rate of doing work with respect to time, its S.I unit is in watts but it can also be expressed in J/s. Power is calculated using the formula:
[tex]Power=\frac{energy}{time}[/tex]
Power is also the rate at which energy is used per second.
Energy is the capacity to do work and it is measured in joules (J).
Power = current × voltage = 7.4 A × 3 V = 22.2 W
[tex]Energy=power*time\\\\time=7.8\ min=7.8*60\ s=468\ s\\\\Energy=22.2*468\\\\Energy=10389.6\ J[/tex]
What is the difference between em waves and mechanical waves?
Answer:
Electromagnetic waves differ from mechanical waves in that they do not require a medium to propagate. This means that electromagnetic waves can travel not only through air and solid materials, but also through the vacuum of space.
Explanation:
Since electromagnetic waves do not require a medium to pass through, they are faster in matter that has fewer particles. ... ~ Sound cannot travel in a vacuum because mechanical waves, such as sound waves, require a medium to propagate through.
4. Tires on the road show how friction produces
a. lubrication
b. heat
c. gravity
d. force
help :(
I think it is D. Force
Answer:
Explanation:
Do you mean tire tracks?
If you do then the tracks show that there must have been a lot of heat involved. When the tires skid, the friction produced must be awfully hot to stop and 800 kg vehical (which is pretty small). The tire tracks that you see are bits of melted rubber taken from the tire.
Force is involved, but heat is the better answer.
gravity is necessary for friction to take place. If you were out in space, you could not get enough friction to leave tire tracks. (Force is awfully small).
Lubrication is there to give you a 4th choice. The exact opposite is what takes place. Lubrication reduces friction.
You are sitting on a Ferris wheel moving at a constant speed of 8 m/s. When you are at the bottom of the rotation, what is the normal force of the seat on you if you have a mass of 50 kg and the radius of the Ferris wheel is 10 m
Answer:
40NExplanation:
Formula for calculating normal force is expressed as:
[tex]F = ma\\since \ a = \frac{v^2}{r} \\F = \frac{mv^2}{r}[/tex]
m is the mass of the body = 50kg
v is the velocity of the Ferris wheel = 8m/s
r is the radius of the Ferris wheel
Substitute into the formula:
[tex]F = \frac{50 \times 8}{10}\\ F = \frac{400}{10}\\ F = 40N\\[/tex]
Hence the normal force of the seat is 40N
The drawing shows two identical airplanes at an air show. The airplanes are flying at the same speed. Airplane W is flying 50 m higher than airplane X. Which statement best describes the energy of the two airplanes?
Answer:
Airplane X has more gravitational potential energy than Airplane W
Explanation:
Gravitational potential energy is defined as "the energy acquired by an object due to its positional change in presence of gravitational force."
That being said, gravitational potential energy depends on the height of an object above the ground. It also depends on the mass of the object and even further, the amount of gravitational force that is applied.
And if we take a look at the question again, we'd agree that the two airplanes are flying at different heights, this means their gravitational potential energy will be different. And as such, Airplane X has more gravitational potential energy than Airplane W
A daring stunt woman sitting on a tree limb
wishes to drop vertically onto a horse gallop-
ing under the tree. The constant speed of the
horse is 6.8 m/s, and the woman is initially
1.91 m above the level of the saddle.
How long is she in the air? The acceleration
of gravity is 9.8 m/s.
Answer in units of s.
Answer:
she is in the air for approximately 0.62 seconds
Explanation:
We want to find the time for a free fall under the acceleration of gravity, covering a distance of 1.91 m, and considering that the woman doesn't impart initial velocity in the vertical direction. So we use the kinematic equation:
[tex]d=v_i\,t+ \frac{g}{2} \,t^21.91 = 0 +4.9\, t^2\\t^2=1.91/4.9\\t=\sqrt{1.91/4.9} \\t\approx 0.624\,\,sec[/tex]
Then she is in the air for approximately 0.62 seconds
Determine the acceleration that results when a 12 N net force is applied to a 3 kg object.
a. 4 m/s 2
b. 6 m/s 2
c. 12 m/s 2
d. 36 m/s 2
Answer:
4m/s^2 ( A)
Explanation:
The solution is in the attached file
If it takes you 5 minutes to dry your hair using a 1200-W hairdryer plugged into a 120-V power outlet, how many Coulombs of charge pass through your hair dryer
Answer:
The charge pass through your hair dryer is 3000 C.
Explanation:
Given that,
Power = 1200 W
Voltage = 120 V
Flow time = 5 min
We need to calculate the current
Using formula of power
[tex]P=VI[/tex]
[tex]I=\dfrac{P}{V}[/tex]
Put the value into the formula
[tex]I=\dfrac{1200}{120}[/tex]
[tex]I=10\ A[/tex]
We need to calculate the charge pass through your hair dryer
Using formula of current
[tex]I=\dfrac{Q}{t}[/tex]
[tex]Q=It[/tex]
Put the value into the formula
[tex]Q=10\times5\times60[/tex]
[tex]Q=3000\ C[/tex]
Hence, The charge pass through your hair dryer is 3000 C.
