Which quantity is the vector? <br> a) weight<br> b) power <br> c) kinetiic energy <br> d) speed

a wave travels at a speed of 793 m/s and has a wavelength of 2.3 meters. calculate the frequency of the wave

Savatey [412]

Answer:

344.8 Hz

Explanation:

The frequency of a wave is given by:

$f=\frac{v}{\lambda}$

where

v is the speed of the wave

$\lambda$ is its wavelength

Here we have

v = 793 m/s

$\lambda=2.3 m$

Substituting into the equation, we find

$f=\frac{793 m/s}{2.3 m}=344.8 Hz$

4 0

3 years ago

6. What is the change in temperature of a metal rod that is 55.0 cm long, decreases length by 0.20 cm, and that has a coefficien

MrMuchimi

Explanation:

We have,

Length of a metal rod is 55 cm or 0.55 m

Change in length is 0.2 cm or 0.002 m

It is required to find the change in temperature of a metal rod. The coefficient of linear expansion is given by :

$\alpha =\dfrac{\Delta L}{L_0\Delta T}$

$\Delta T$ is the change in temperature

$\Delta T =\dfrac{\Delta L}{L_0\alpha }\\\\\Delta T =\dfrac{0.002}{0.55\times 12\times 10^{-6}}\\\\\Delta T= 303.03^{\circ} C$

So, the change in temperature is 303.03 degrees Celsius.

4 0

3 years ago

An empty rubber balloon has a mass of 12.5 g. The balloon is filled with helium at a density of 0.181 kg/m3. At this density the

Taya2010 [7]

Answer:

5.5 N

Explanation:

mass of balloon (m) = 12.5 g = 0.0125 kg

density of helium = 0.181 kg/m^{3}

radius of the baloon (r) = 0.498 m

density of air = 1.29 kg/m^{3}

acceleration due to gravity (g) = 1.29 m/s^{2}

find the tension in the line

the tension in the line is the sum of all forces acting on the line

Tension =buoyant force + force by helium + force of weight of rubber

force = mass x acceleration

from density = \frac{mass}{volume} , mass = density x volume

buoyant force = density x volume x acceleration

where density is the density of air for the buoyant force

buoyant force = 1.29 x (\frac{4]{3} x π x 0.498^{3}) x 9.8 = 6.54 N

force by helium = density x volume x acceleration

force by helium = 0.181 x (\frac{4]{3} x π x 0.498^{3}) x 9.8 = 0.917 N

force of its weight = mass of rubber x acceleration

force of its weight = 0.0125 x 9.8 = 0.1225 N

Tension = buoyant force + force by helium + force of weight of rubber

the force of weight of rubber and of helium act downwards, so they

carry a negative sign.

Tension = 6.54 - 0.917 - 0.1225 = 5.5 N

8 0

3 years ago

Tech A says that a vacuum modulator converts manifold vacuum into an engine load signal. Tech B says that the manual valve is mo

alexandr1967 [171]

Answer:

The correct option for the answer is A.) Tech A

Explanation:

Tech A is correct

8 0

3 years ago

It takes 4.0 eV to excite an electron in a box from the ground level to the first excited level. What is the width L of the box?

AveGali [126]

To solve this problem we will use the concept related to electrons in a box which determines the energy of an electron in that state.

Mathematically this expression is given by,

$E_n= \frac{n^2h^2}{8mL^2}$

Where,

m = mass of an electron

h = Planck's constant

n = is the integer number of the eigenstate

L = Quantum well width

The change in energy must be given in state 1 and 2, therefore

$\Delta E = E_2 - E_1$

$\Delta E = \frac{2^2h^2}{8mL^2}-\frac{1^2h^2}{8mL^2}$

$\Delta E = \frac{3h^2}{8mL^2}$

Replacing we have:

$(4*1.6*10^{-19}) = \frac{3(6.626*10^{34})}{8*(9.11*10^{-31})*L^2}$

$L = 0.53nm$

Therefore the correct answer is C.

6 0

3 years ago

Which quantity is the vector? a) weight b) power c) kinetiic energy d) speed