All categories

3 years ago

The current in an electric hair dryer is 10

1 answer:

8 0

First let's convert the time in seconds:
$\Delta t= 5 min= 5 min \cdot (60 s/min)= 300 s$

The current is defined as the quantity of charge flowing through a certain section of a circuit per unit of time:
$I= \frac{Q}{\Delta t}$
Using I=10 A, and $\Delta t=300 s$ , we can find the amount of charge flown through the hair dryer in this time:
$Q=I \Delta t=(10 A)(300 s)=3000 C$

The charge of a single electron is $q=1.6 \cdot 10^{-19} C$ , so the number of electrons flown through the hair dryer is the total charge divided by the charge of a single electron:
$N= \frac{Q}{q}= \frac{3000 C}{1.6 \cdot 10^{-19} C} =1.88 \cdot 10^{22}$

You might be interested in

Which of the following would decrease the resistance to the flow of an electric current through a body?

Nookie1986 [14]

R = ρ L/A. R= resistance, ρ= resistivity, L= length of the conductor. A = area of the conductor. Resistance is directly proportional to the length of the conductor. So if length of the conductor is decreased, resistance will also decrease. Hence A is the correct option

3 0

3 years ago

Read 2 more answers

Please answer these: Q1. i. In what two ways combustion can be useful to us? Explain by giving examples. ii. Explain why decompo

kenny6666 [7]

Answer:

1) combustion can be used as a source of energy.

Combustion is used to power rockets

ii) Decomposition of sugar is a chemical change and new substances are formed.

2)corrosion of pipes

Corrosion of bridges

Corrosion of knives and blades at home

I) iron rusts due to the action of air and moisture bon the metal setting up an electrochemical process in which the iron is the anode. This leads to the corrosion of the iron metal.

ii) Rusting is a problem because it reduces the economic value of iron. Rust weakens iron and threatens the integrity of materials made from iron.

Iron rusting may lead to the collapse of a bridge

Iron rusting makes a blade blunt

Iron rusting weakens pipes made of iron

iii) Rusting of iron can be prevented by galvanizing the iron or by painting the iron.

3) chemical change leads to the formation of a new substance while physical change does not lead to the formation of a new substance.

Chemical changes are not easily reversible while physical changes are easily reversible.

ii)condensation of water vapour is a physical change

iii)

Electrolysis of water;

Two moles of water---> two moles of hydrogen gas + one mole of oxygen gas

Synthesis of water;

two moles of hydrogen gas + one mole of oxygen gas---->Two moles of water

Decomposition of sugar;

One mole of Sucrose---> twelve moles of carbon + eleven moles of water + heat

Six moles of carbon dioxide + six moles of water +energy------> one mole of sugar + six moles of oxygen

Explanation:

Combustion is useful as a source of energy because it is used in power generation. Currently, combustion is being used to power rockets. It is also used as a way of providing heat at home.

One of the characteristics of a chemical change is that it leads to the formation of new substances. Since the decomposition of sugar leads to the formation of carbon and water, it is an irreversible chemical change.

When water is heated, it is converted into vapour which can settle on a surface and convert back to liquid water. This is a physical change.

6 0

3 years ago

A small propeller airplane can comfortably achieve a high enough speed to take off on a runway that is 1/4 mile long. A large, f

QveST [7]

Answer:

1 mile

Explanation:

We can use the following equation of motion to solve for this problem:

$v^2 - v_0^2 = 2a\Delta s$

where v m/s is the final take-off velocity of the airplane, $v_0 = 0$ initial velocity of the can when it starts from rest, a is the acceleration of the airplanes, which are the same, and $\Delta s$ is the distance traveled before takeoff, which is minimum runway length: