All categories

3 years ago

An electric Kettle is rated at 25 W. Calculate the quantity of heat generated in 2s

Physics

1 answer:

MatroZZZ [7]3 years ago

4 0

Answer:

Energy consumed by the electric kettle in 9.5 min =Pt=(2.5×10

)×(9.5×60)=14.25×10

Energy usefully consumed =msΔT=3×(4.2×10

)×(100−15)=10.71×10

where s=4.2J/g

C= specific heat of water and boiling point temp=100

Heat lost =14.25×10

−10.71×10

=3.54×10

You might be interested in

Newton’s empirical law of cooling/warming of an object is given by ( ), T Tm k dt dT = − where k is a constant of proportionalit

pychu [463]

Answer:

The time for the cake to cool off to room temperature is

approximately 30 minutes.

Let $T_{0}$ = $70^{0}$ F be the temperature and T that of the body

Explanation:

Our Tm = 70, the initial-value problem is

$\frac{DT}{dt}$ = k(T − 70), T(0) = 300

Solving the equation, we get

$\frac{DT}{t-70}$ = kdt

In [T-70]= kt + $C_{1}$

T = 70 + $C_{2}$ $e^{kt}$

Finding he value for $C_{2}$ using the initial value of T (0)= 300, therefore we get:

300=70+ $C_{2}$

$C_{2}$ = 230 therefore

T= 70+ 230 $e^{kt}$

Finding the value for k using T (3) = 200, therefore we get

T (3) = 200

$e^{3k}$ = $\frac{13}{23}$

K = $\frac{1}{3}$ in $\frac{13}{23}$

= -0.19018

Therefore

T(t) = 70+230 $e^{-0.19018}$

4 0

2 years ago

Observe yourself breathing and count the number of times you inhale per second. During each breath you probably inhale 0.66 L of

Pavel [41]

To solve this exercise it is necessary to apply the concepts related to Robert Boyle's law where:

$PV=nRT$

Where,

P = Pressure

V = Volume

T = Temperature

n = amount of substance

R = Ideal gas constant

We start by calculating the volume of inhaled O_2 for it:

$V = 21\% * 0.66L$

$V = 0.1386L$

Our values are given as

P = 1atm

T=293K $R = 0.083145kJ*mol^{-1}K^{-1}$

Using the equation to find n, we have:

$PV=nRT$

$n = \frac{PV}{RT}$

$n = \frac{(1)(0.1386)}{(0.0821)(293)}$

$n = 5.761*10^{-3}mol$

Number of molecules would be found through Avogadro number, then

$\#Molecules = 5.761*10^{-3}*6.022*10^{23}$

$\#Molecules = 3.469*10^{21} molecules$

7 0

3 years ago

Material that slows down or resists the flow of current. these are used in electric circuits to help control the flow of current

Nataly_w [17]

It's called an insulator

3 0

3 years ago

3. Do you have an issue with the NSA monitoring citizens’ phone calls, text messages, emails, etc.?

goblinko [34]

If You Have Nothing to Hide, You Have Nothing to Fear

8 0

3 years ago

When astronauts get on a rocket and go outside Earth they float because gravity is affected by this

V125BC [204]

Answer:

Distance

Explanation:

Gravity is indirectly related to distance. This means if distance increases, gravitational pull decreases.

8 0

3 years ago