Define average speed velocity

The H line in Calcium is normally at 396.9nm. however, in a star’s spectrum it is measured at 398,1 nm. How fast is the star mov

konstantin123 [22]

H line of Calcium spectrum is normally given as 396.9 nm

Now from a distant star we measured it as 398.1 nm

So here this change in the wavelength of distant star is due to Doppler's effect of light as per which when source of light moves towards the observer then the frequency of light received will appear different from its actual frequency

So here we can say as per Doppler's effect of light

$\frac{\Delta \nu}{\nu_0} = \frac{v}{c}$

$\frac{\nu' - \nu}{\nu_0} = \frac{v}{c}$

$\frac{\frac{1}{\lambda} - \frac{1}{\lambda'}}{\frac{1}{\lambda}} = \frac{v}{c}$

$\frac{\lambda' - \lambda}{\lambda'} = \frac{v}{c}$

given that

$\lambda' = 398.1 nm$

$\lambda = 396.9 nm$

$c = 3 * 10^8 m/s$

$\frac{398.1 - 396.9}{398.1} = \frac{v}{3*10^8}$

$v = 3*10^8 * \frac{1.2}{398.1}$

$v = 9.04 * 10^5 m/s$

so the start is moving away with speed 9.04 * 10^5 m/s because when wavelength is more than the real wavelength then its frequency is less which mean it is moving away from the Earth

5 0

3 years ago

Una tractomula se desplaza con rapidez de 69 km/h. Cuando el conductor ve una vaca atravesada enmedio de la carretera, acciona l

Anestetic [448]

Answer:

Los datos que tenemos:

Rapidez: 69km/h

Tiempo que tarda en frenar = 4s.

Distancia inicial entre la tracto-mula y la vaca = 25m

Ok, la ecuación de desaceleración es:

D = (sf - si)/t

sf = velocidad final = 0m/s

si = velocidad inicial = 69km/h

t = tiempo = 4s

D = -69km/h/4s

ok, 1h = 3600s

D = (-69km/s)*1/(4*3600s) = -0.0048 km/s^2

Entonces la ecuación de aceleración es:

a(t) = -0.0048 km/s^2

Para la velocidad, integramos sobre el tiempo

v(t) = (-0.0048 km/s^2)*t + v0

donde v0 es la velocidad inicial, en este caso v0 = 69km/3600s = 0.0191km/s

v(t) = (-0.0048 km/s^2)*t + 0.0191km/s

Para la posición volvemos a integrar sobre el tiempo, esta vez suponemos la posición inicial igual a cero.

p(t) = (1/2)*(-0.0048 km/s^2)*t^2 + 0.0191m/s*t

Ahora, si p(t=4s) < 25m, esto implica que la tracto-mula no impacto con la vaca.

p(4s) = (1/2)*(-0.0048 km/s^2)*(4s)^2 + 0.0191km/s*4s = 0.038km

y 1km = 1000m

0.038km = 0.038*1000m = 38m

Entonces si, atropello a la vaca.

4 0

4 years ago

Gordon throws a baseball into the air. It rises, stops when it reaches its greatest height, and then falls back down to the grou

Arte-miy333 [17]

Answer:

A) When the baseball is rising

Explanation:

When an object like the baseball is thrown into the air, the kinetic energy is gradually converted into potential energy. When the baseball rises to its maximum height, the kinetic energy becomes zero and the kinetic energy is fully converted into potential energy.

7 0

3 years ago

A child holds one end of a 33.0-meter long rope in her hand and moves it up-and-down to produce a sinusoidal wave by moving her

WITCHER [35]

Answer:

Wavelength=75 cm.

The wavelength well remain unchanged which is 75 cm.

Explanation:

The formula which will help us to answer the question is:

V=f*λ

Where:

V is the velocity

f is the frequency of wave

λ is the wave length

Now:

λ=V/f Eq (1)

The equation show's that wavelength is independent of the amplitude but it depends on the frequency and the velocity with which wave is moving.

The wavelength well remain unchanged which is 75 cm.

6 0

3 years ago

ListenA bicycle and its rider have a combined mass of 80. kilograms and a speed of 6.0 meters per second. What is the magnitude

Setler [38]

Answer:

a) $1.2\times 10^2\ N$

Explanation:

t = Time taken

u = Initial velocity

v = Final velocity

a = Acceleration

$v=u+at\\\Rightarrow a=\frac{v-u}{t}\\\Rightarrow a=\frac{0-6}{4}\\\Rightarrow a=-1.5\ m/s^2$

The acceleration of the bicycle and rider is -1.5 m/s²

Force

$F=ma\\\Rightarrow F=80\times -1.5\\\Rightarrow F=-120\ N=-1.2\times 10^2\ N$

The magnitude of the average force needed to bring the bicycle and its rider to a stop is $1.2\times 10^2\ N$

3 0

3 years ago

Define average speed velocity​

Define average speed velocity