All categories

2 years ago

A student weighs a sample of an unkown metal and finds the mass to be 39.27g what is the metal?

Physics

1 answer:

xxTIMURxx [149]2 years ago

7 0

The unknown metal with a mass of 39.27 g is potassium with the symbol K.

The mass of an atom is due to protons and neutrons present in it.

The protons and neutrons are together present in the nucleus of an atom.

The mass of any element is given by its mass number whose formula is

Mass Number = Number of protons + Number of neutrons

In the given case 39 = Number of protons + Number of neutrons

The only element of the periodic table which satisfies the above equation is potassium because it has 19 protons and 20 neutrons.

Thus, the unknown metal with a mass of 39.27 g is potassium with the symbol K.

To know more about "mass number", refer to the following link:

brainly.com/question/4408975?referrer=searchResults

#SPJ4

You might be interested in

An egg is dropped from the top of the band hall. if the band hall is 25 m tall, determine the time it takes the egg to hit the f

Vera_Pavlovna [14]

Answer:

2.26 s

Explanation:

The following data were obtained from the question:

Height (h) = 25 m

Acceleration due to gravity (g) = 9.8 m/s²

Time (t) =..?

The time taken for the egg to hit the floor can be obtained as illustrated below:

h = ½gt²

25 = ½ × 9.8 × t²

25 = 4.9 × t²

Divide both side by 4.9

t² = 25 / 4.9

Take the square root of both side

t = √(25 / 4.9)

t = 2.26 s

Thus, it will take 2.26 s for the egg to hit the floor.

7 0

3 years ago

Consider the Uniform Circular Motion Gizmo configured as shown. Notice that, under the current settings, |a|=0.50m/s2. What chan

Eddi Din [679]

To increase the centripetal acceleration to $2.00 m/s^2$ , you can double the speed or decrease the radius by 1/4

Explanation:

An object is said to be in uniform circular motion when it is moving at a constant speed in a circular path.

The acceleration of an object in uniform circular motion is called centripetal acceleration, and it is given by

$a=\frac{v^2}{r}$

where

v is the speed of the object

r is the radius of the circular path

In the problem, the original centripetal acceleration is

$a=0.50 m/s^2$

We want to increase it by a factor of 4, i.e. to

$a'=2.00 m/s^2$

We notice that the centripetal acceleration is proportional to the square of the speed and inversely proportional to the radius, so we can do as follows:

- We can double the speed:

v' = 2v

This way, the new acceleration is

$a'=\frac{(2v)^2}{r}=4(\frac{v^2}{r})=4a$

so, 4 times the original acceleration

- We can decrease the radius to 1/4 of its original value:

$r'=\frac{1}{4}r$

So the new acceleration is

$a'=\frac{v^2}{(r/4)}=4(\frac{v^2}{r})=4a$

so, the acceleration has increased by a factor 4 again.

Learn more about centripetal acceleration:

brainly.com/question/2562955

brainly.com/question/6372960

#LearnwithBrainly

5 0

3 years ago

The radius of earth is 6,370,000 m. Express this measurement in km in scientific notation with the correct number of significant

AlexFokin [52]

Answer:

6.37 x 10³ Km

Explanation:

given,

Radius of earth = 6,370,000 m

we know,

1 km = 1000 m

1 m = 0.001 Km

6,370,000 m = 6,370,000 x 0.001

= 6,370 Km

The number 6,370 has 3 significant figure.

To transform this to an exponential number, it is necessary to move the decimal to the left so there is only one digit in front of the decimal point.

Representing the given number in scientific notation

= 6.37 x 10³ Km

7 0

3 years ago

A concert loudspeaker suspended high off the ground emits 34 W of sound power. A small microphone with a 1.0 cm2 area is 44 m fr

rjkz [21]

Answer:

Part A

I = 1.4 mW/m²

Part B

β = 91.46 dB

Explanation:

Part A

Sound intensity is the power per unit area of sound waves in a direction perpendicular to that area. Sound intensity is also called acoustic intensity.

For a spherical sound wave, the sound intensity is given by;

$I = \frac{P}{A}$

$I = \frac{P}{4\pi r^{2}}$

Where;

P is the source of power in watts (W)

I is the intensity of the sound in watt per square meter (W/m2)

r is the distance r away

Given:

P = 34 W,

A = 1.0 cm²

r = 44 m

The sound intensity at the position of the microphone is calculated to be;

$I = \frac{34}{4\pi (44)^{2}}$

I = 0.0013975 W/m²

≈ I = 0.0014 W/m² = 1.4 × 10⁻³ W/m²

I = 1.4 mW/m²

The sound intensity at the position of the microphone is 1.4 mW/m².

Part B

Sound intensity level or acoustic intensity level is the level of the intensity of a sound relative to a reference value. It is a a logarithmic quantity. It is denoted by β and expressed in nepers, bels, or decibels.

Sound intensity level is calculated as;

β $= 10log_{10}\frac{I}{I_{0}}$ dB

Where,

β is the Sound intensity level in decibels (dB)

I is the sound intensity;

I₀ is the reference sound intensity;

By pluging-in, I₀ is 1.0 × 10⁻¹² W/m²

∴ β $= 10log_{10}\frac{1.4 * 10^{-3} W/m^{2}}{1.0 * 10^{-12} W/m^{2}}$

β $= 10log_{10} (1.4 * 10^{9})$

β = 91.46 dB

The sound intensity level at the position of the microphone is 91.46 dB.

4 0

3 years ago

What will be the ratio between the initial and final kinetic energy of a car, if its velocity is tripled?

Katarina [22]

Answer:b

Explanation:

7 0

2 years ago