The spectra for elements are ____

To practice Problem-Solving Strategy 25.1 Power and Energy in Circuits. A device for heating a cup of water in a car connects to

Rom4ik [11]

Answer:

It takes <u>951 seconds</u> to boil a cup of water.

Explanation:

Given:

EMF of the battery (E) = 10.0 V

Internal resistance of the battery (r) = 0.04 Ω

Resistance of the circuit = 'R'

Current measured in the circuit (I) = 11.0 A

Energy required to boil water (U) = 100 kJ = 100 × 10³ J [1 kJ = 10³ J]

Time taken for boiling (t) = ?

We know that, the emf of the battery is given as:

$E=I(R+r)$

Plug in the given values and solve for 'R'. This gives,

$10=11(R+0.04)\\\\R+0.04=\frac{10}{11}\\\\R=\frac{10}{11}-0.04=0.909-0.04=0.869\ \Omega$

Now, energy required to boil the water is given as:

$U=I^2Rt$

Plug in the given values and solve for 't'. This gives,

$100\times 10^3\ J=(11.0\ A)^2(0.869\ \Omega)t\\\\t=\frac{100000\ J}{121\times 0.869\ A^2\Omega}\\\\t=\frac{100000\ J}{105.149\ A^2\Omega}\\\\t=951\ s$

So, it takes 951 seconds to boil a cup of water.

5 0

3 years ago

Multiply 2 cm by 100 to convert to meters

zavuch27 [327]

Answer:

1m= 100cm

?= 2cm let ? be (n)

cross multiply

100n = 2

n= 2÷100

n= 0.02m

therefore 2cm is equal to 0.02 m

5 0

3 years ago

A space station, in the form of a spoked wheel 120 m in diameter, rotates to provide an artificial gravity of 3.00 m/s² for pers

lubasha [3.4K]

Answer:

2.12 rpm

Explanation:

$a_c= Centripetal\ acceleration=3.00\ m/s^2\\r=radius=\frac {120}{2}=60\ m\\a_c=\frac {v^2}{r}\\\Rightarrow v^2=a_c\times r\\\Rightarrow v^2=3\times 60=180\\\Rightarrow v=\sqrt{180}=13.41\ m/s\\$

$v=\omega r\\\Rightarrow \omega=\frac {v}{r}\\\Rightarrow \omega=\frac {13.41}{60}\\\Rightarrow \omega=0.2236\ rad/s\\1\ rad/s=9.55\ rpm\\\Rightarrow 0.2236\ rad/s=2.12\ rpm\\\therefore Wheel\ rotations=2.12\ rpm$

3 0

3 years ago

How is the control group and experimental group different

zzz [600]

The control group is the independent variable and the experimental group is the dependent due to change during the experiment. The experimental group will usually rely on another variable in the experiment for change.

4 0

3 years ago

Suppose a fireworks shell explodes, breaking into three large pieces for which air resistance is negligible. How is the motion o

denis-greek [22]

The center of mass isn't affected by the explosion.

To find the answer, we need to know about the trajectory of motion at zero external force.

<h3>How is the trajectory of an object changed when the net external force on it is zero?</h3>

When there's no net external force acting on an object, its momentum doesn't change with time.
As its momentum doesn't change, so it continues with the original trajectory.

<h3>Why doesn't the trajectory of firework change when it's exploded?</h3>

When a firework is exploded, its internal forces are changed, but there's no external force.
So, although the fragments follow different trajectories, but the trajectory of center of mass remains unchanged.

Thus, we can conclude that the center of mass isn't affected by the explosion.

Learn more about the trajectory of exploded firework here:

brainly.com/question/17151547

#SPJ4

3 0

2 years ago

The spectra for elements are _____.