Ask question

Ask question

All categories

3 years ago

13

A hair dryer uses 1100 W of power

2 answers:

weqwewe [10]3 years ago

5 0

Answer:10

Explanation:acellus

dedylja [7]3 years ago

4 0

Answer: 11

Explanation:

You might be interested in

Find a glass jar with a screw-top metal lid. Close the lid snugly and put the jar into the refrigerator. Leave it there for abou

DochEvi [55]

Answer:

The lid becomes tighter

It becomes tighter because metals have a lower heat capacity than glass meaning their temperature drops (or increases) much faster than glass for the same energy change. So in this example, the metal will contract faster than the glass causing it to be more tighter around the glass.

5 0

4 years ago

If you want to double the kinetic energy of a gas molecule, by what factor must you increase its momentum?A) 16B) 2^(1/2)

worty [1.4K]

Answer: $\sqrt{2}$

The linear momentum $p$ is given by the following equation:

$p=m.v$ (1)

Where $m$ is the mass and $v$ the velocity.

On the other hand, the kinetic energy $K$ is given by:

$K=\frac{p^{2}}{2m}$ (2)

Which is the same as:

$K=\frac{1}{2}m.v^{2}$

Now, if we double the kinetic energy, equation (2) changes to:

$2K=2\frac{p^{2}}{2m}$

$2K=\frac{p^{2}}{m}$ (3)

So, if we want to obtain the kinetic energy as shown in (3), the only option that works is increasing momentum by a factor of $\sqrt{2}$ or $2^{1/2}$ :

Applying this in (2):

$K=\frac{(\sqrt{2}p)^{2}}{2m}$

$K=\frac{(2p)^{2}}{2m}$

$K=\frac{p^{2}}{m}$ >>>As we can see, this equation is the same as equation (3)

Therefore, the correct answer is B

3 0

3 years ago

Bill is farsighted and has a near point located 119 cm from his eyes. Anne is also farsighted, but her near point is 70.0 cm fro

Gennadij [26K]

Answer:

Explanation:

For Bill's glasses)

d_o=25 cm-2 cm=23.2 cm

d_i=129 cm-2 cm=127 cm

We know that

$1 / f = 1 / d_o + 1 / d_i
$

$f=(1 / d_o + 1 / d_i)^-1
$

so plug the numbers in

$f = (1 / (23) + 1 / (127))^-1
$

= 28.08 cm

For Anna's glasses)

d_o=25 cm-2 cm=23 cm

d_i=70.0 cm-2 cm=68 cm

Same thing

$(1 / f = 1 / d_o + 1 / d_i
)$

$f=(1 / do + 1 / di)^-1
$

so plug the numbers in

$f = (1 / (23) + 1 / (68))^-1
$

= 17.21 cm

5 0

3 years ago

Why is this website not work how i want it this is so annoying

Mice21 [21]

It depends how you want it to work do you want to take a picture oh yea and to do that you must create a account btw

5 0

3 years ago

Read 2 more answers

A ruby laser delivers a 16.0-ns pulse of 4.20-MW average power. If the photons have a wavelength of 694.3 nm, how many are conta

stepan [7]

Answer:

The value is $n = 2.347 *10^{17} \ photons$

Explanation:

From the question we are told that

The amount of power delivered is $P = 4.20 \ M W = 4.20 *10^{6} \ W$

The time taken is $t = 16.0ns = 16.0 *10^{-9} \ s$

The wavelength is $\lambda = 694.3 \ nm = 694.3 *10^{-9} \ m$

Generally the energy delivered is mathematically represented as

$E = P * t = \frac{n * h * c }{\lambda }$

Where $h$ is the Planck's constant with value $h = 6.262 *10^{-34} \ J \cdot s$

c is the speed of light with value $c = 3.0*10^{8} \ m/s$

So

$4.20 *10^{6} * 16*10^{-9}= \frac{n * 6.626 *10^{-34} * 3.0*10^{8} }{694.3 *10^{-9}}$

=> $n = 2.347 *10^{17} \ photons$

4 0

3 years ago