1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Liono4ka [1.6K]
3 years ago
10

A battery has an emf of 15.0 V. The terminal voltage of the battery is 12.2 V when it is delivering 14.0 W of power to an extern

al load resistor R. (a) What is the value of R?
(b) What is the internal resistance of the battery?
Physics
1 answer:
solong [7]3 years ago
3 0

Answer:

The value of R and the internal resistance of the battery are 10.6 ohm and 2.45 ohm

Explanation:

Given that,

Emf of battery = 15.0 V

Voltage = 12.2 V

Power = 14.0 W

(a). We need to calculate the value of R

Using formula of power

P=IV

P=\dfrac{V^2}{R}

R=\dfrac{V^2}{P}

Where, R = resistance

P = power

V = voltage

Put the value into the formula

R =\dfrac{(12.2)^2}{14.0}

R=10.6\ \Omega

(b). We need to calculate the internal resistance of the battery

Firstly we calculate the current

Using formula of current

I=\dfrac{V}{R}=\dfrac{P}{V}

Put the value of P and V into the formula

I =\dfrac{14}{12.2}

I=1.14\ A

We calculate the internal resistance

Using formula of emf

e-V=Ir

r =\dfrac{e-V}{I}

Put the value into the formula

r=\dfrac{15.0-12.2}{1.14}

r = 2.45\ \Omega

Hence, The value of R and the internal resistance of the battery are 10.6 ohm and 2.45 ohm

You might be interested in
Which of the following tools can be used to determine humidity? Select all that apply
Y_Kistochka [10]
Thermometer there's others you can use but i know that's one of them
7 0
3 years ago
Read 2 more answers
What is the force required to move a block of mass 150 pound by a distance of 5ft in 8 seconds?
Nadusha1986 [10]

Force required to move a block is 1.615 N

Given:

mass of block = m = 150 pounds = 68 kg

distance = d = 5 ft = 1.52 metres

time = t = 8 sec

To Find:

force required to move the block

Solution: Force is defined as product of mass and acceleration and it's unit is N or Newton.

Velocity = displacement/ time = 1.52 / 8 = 0.19 m/s

Acceleration = velocity/time = 0.19/8 =

0.023 m/s^2

Force = mass x acceleration = 68x0.023 = 1.615 N

Hence, force required to move the block is 1.615 N

Learn more about Force here:

brainly.com/question/12970081

#SPJ4

8 0
1 year ago
Model rocket engines are sized by thrust, thrust duration, and total impulse, among other characteristics. A size C5 model rocke
umka2103 [35]

Answer:

v_{f} = 115.95 m / s

Explanation:

This is an exercise of a variable mass system, let's form a system formed by the masses of the rocket, the mass of the engines and the masses of the injected gases, in this case the system has a constant mass and can be solved using the conservation the amount of movement. Which can be described by the expressions

        Thrust = v_{e}  \frac{dM}{dt}

        v_{f}-v₀ = v_{e} ln ( \frac{M_{o} }{M_{f}} )

where v_{e} is the velocity of the gases relative to the rocket

let's apply these expressions to our case

the initial mass is the mass of the engines plus the mass of the fuel plus the kill of the rocket, let's work the system in SI units

       M₀ = 25.5 +12.7 + 54.5 = 92.7 g = 0.0927 kg

     

The final mass is the mass of the engines + the mass of the rocket

      M_{f} = 25.5 +54.5 = 80 g = 0.080 kg

thrust and duration of ignition are given

       thrust = 5.26 N

       t = 1.90 s

Let's start by calculating the velocity of the gases relative to the rocket, where we assume that the rate of consumption is linear

          thrust = v_{e} \frac{M_{f} - M_{o}  }{t_{f} - t_{o}  }

          v_{e} = thrust  \frac{\Delta t}{\Delta M}

          v_{e} = 5.26 \frac{1.90}{0.080 -0.0927}

          v_{e} = - 786.93 m / s

the negative sign indicates that the direction of the gases is opposite to the direction of the rocket

now we look for the final speed of the rocket, which as part of rest its initial speed is zero

            v_{f}-0 = v_{e} ln ( \frac{M_{o} }{M_{f} } )

we calculate

            v_{f} = 786.93 ln (0.0927 / 0.080)

            v_{f} = 115.95 m / s

5 0
3 years ago
The gauge pressure at the bottom of a cylinder of liquid is 0.30atm. The liquid is poured into another cylinder with twice the r
likoan [24]

Answer:

P_g' = 0.075 atm

Explanation:

Gauge pressure at the bottom of the cylinder depends on the height of water in the cylinder

So here we can say that

P_g = \rho g h

now when liquid is filled to height "h" in base area "A" then gauge pressure of the liquid at the bottom is given as

P_g = 0.30 atm

now we put the whole liquid into another cylinder with twice radius of the first cylinder

So area becomes 4 times

now by volume conservation we can say that if area is increased by 4 times then height of liquid will decrease by 4 times

so we have

h' = \frac{h}{4}

so gauge pressure is given as

P_g' = \frac{0.30}{4} = 0.075 atm

5 0
3 years ago
A baseball m=.34kg is spun vertically on a massless string of length l=.52m. the string can only support a tension of tmax=9.9n
larisa86 [58]
<span>4.5 m/s This is an exercise in centripetal force. The formula is F = mv^2/r where m = mass v = velocity r = radius Now to add a little extra twist to the fun, we're swinging in a vertical plane so gravity comes into effect. At the bottom of the swing, the force experienced is the F above plus the acceleration due to gravity, and at the top of the swing, the force experienced is the F above minus the acceleration due to gravity. I will assume you're capable of changing the velocity of the ball quickly so you don't break the string at the bottom of the loop. Let's determine the force we get from gravity. 0.34 kg * 9.8 m/s^2 = 3.332 kg m/s^2 = 3.332 N Since we're getting some help from gravity, the force that will break the string is 9.9 N + 3.332 N = 13.232 N Plug known values into formula. F = mv^2/r 13.232 kg m/s^2 = 0.34 kg V^2 / 0.52 m 6.88064 kg m^2/s^2 = 0.34 kg V^2 20.23717647 m^2/s^2 = V^2 4.498574938 m/s = V Rounding to 2 significant figures gives 4.5 m/s The actual obtainable velocity is likely to be much lower. You may handle 13.232 N at the top of the swing where gravity is helping to keep you from breaking the string, but at the bottom of the swing, you can only handle 6.568 N where gravity is working against you, making the string easier to break.</span>
7 0
3 years ago
Read 2 more answers
Other questions:
  • The x coordinate of an electron is measured with an uncertainty of 0.200 mm . What is vx, the x component of the electron's velo
    15·1 answer
  • Two airplanes leave an airport at the same time. The velocity of the first airplane is 750 m/h at a heading of 51.3°. The veloci
    14·2 answers
  • How much work is done in lifting a 6 kg object from the ground to a height of 4m?
    15·1 answer
  • The electromagnetic spectrum is composed of many colors that possess different wavelengths. Which color possesses the shortest?
    7·1 answer
  • A boy pushes a cart with a constant velocity of 0.5m/s by applying a force of 60 N. What is the total frictional force acting on
    9·1 answer
  • You measure the voltage difference of a circuit to be 15 Volts and the resistance to be 675 Ohms.
    15·1 answer
  • What is a black hole's escape velocity?
    6·1 answer
  • According to the chart which type of electromagnetic wave has a longest wavelength?
    6·1 answer
  • Need help guys please
    11·1 answer
  • S Four point charges each having charge Q are located at the corners of a square having sides of length a. Find expressions for(
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!