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MaRussiya [10]
3 years ago
8

g An astronaut must journey to a distant planet, which is 189 light-years from Earth. What speed will be necessary if the astron

aut wishes to age only 12 years during the round trip? (Give your answer accurate to four decimal places.)
Physics
1 answer:
Butoxors [25]3 years ago
5 0

Answer:

The value is v  =  2.999 *10^{8} \  m/s

Explanation:

From the question we are told that

   The time taken to travel to the planet from earth is t = 189 \ light-years

    The  time to be spent on the ship is  t_{s} =  12 \  years

Generally speed can be obtained using the mathematical relation represented below

       t_s  =  2 * t *  \sqrt{1 -  \frac{v^2}{c^2 } }

The 2 in the equation show that the trip is a round trip i.e going and coming back

=>    12 =  2 * 189 *  \sqrt{1 -  \frac{v^2}{(3.0*10^{8})^2 } }

=>     v  =  2.999 *10^{8} \  m/s

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Gre4nikov [31]

Explanation:

1.

We use the equation

h = \frac{gt^2}{2}, where

h is the height traveled,

g is the acceleration due to gravity and

t is the time taken to reach height h.

We can now calculate t to be

\sqrt{\frac{2*1.2 m}{9.81 m/s^2} }

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Let v be the initial velocity of the player.

The player deaccelarates from v m/s to 0 m/s in 0.495 s at the rate of 9.81 m/s^2.

v = 9.81 m/s^2 x 0.495 s = 4.85 m/s

2.

The player takes 0.3 s to increase his velocity from 0 m/s to 4.85 m/s. So his average accelaration is

4.85 m/s / 0.3 s = 16.2 m/s^2

5 0
3 years ago
An airliner arrives at the terminal, and its engines are shut off. The rotor of one of the engines has an initial clockwise angu
Ilia_Sergeevich [38]

(a) 1200 rad/s

The angular acceleration of the rotor is given by:

\alpha = \frac{\omega_f - \omega_i}{t}

where we have

\alpha = -80.0 rad/s^2 is the angular acceleration (negative since the rotor is slowing down)

\omega_f is the final angular speed

\omega_i = 2000 rad/s is the initial angular speed

t = 10.0 s is the time interval

Solving for \omega_f, we find the final angular speed after 10.0 s:

\omega_f = \omega_i + \alpha t = 2000 rad/s + (-80.0 rad/s^2)(10.0 s)=1200 rad/s

(b) 25 s

We can calculate the time needed for the rotor to come to rest, by using again the same formula:

\alpha = \frac{\omega_f - \omega_i}{t}

If we re-arrange it for t, we get:

t = \frac{\omega_f - \omega_i}{\alpha}

where here we have

\omega_i = 2000 rad/s is the initial angular speed

\omega_f=0 is the final angular speed

\alpha = -80.0 rad/s^2 is the angular acceleration

Solving the equation,

t=\frac{0-2000 rad/s}{-80.0 rad/s^2}=25 s

6 0
3 years ago
Para que el calor sea transmitido por conducción los cuerpos deben tocarse?<br> verdadero o falso
dybincka [34]

Answer:

verdadero

Explanation:

Conducción:Es la más sencilla de entender, consiste en la transferencia de calor entre dos puntos de un cuerpo que se encuentran a diferente temperatura, sin que se produzca transferencia de materia entre ellos.

7 0
2 years ago
If a player through a basketball to the target with an initial velocity of 17 m/s making an angle of 30 degrees with the horizon
Svetllana [295]

Answer:

The final position made with the vertical is 2.77 m.

Explanation:

Given;

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time of motion, t = 1.3 s

The vertical component of the velocity is calculated as;

V_y = Vsin \theta\\\\V_y = 17 \times sin(30)\\\\V_y = 8.5 \ m/s

The final position made with the vertical (Yf) after 1.3 seconds is calculated as;

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Therefore, the final position made with the vertical is 2.77 m.

3 0
2 years ago
Which sentence best describes a role of gravity in the formation of the
enyata [817]

Answer:

I think it's option D

Explanation:

I think it's option D but not so sure

8 0
3 years ago
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