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3 years ago

6

a train travles at a speed of 30m/s. the train starts at an initial position of 1000 meters and travels for 30 seconds. what is

its final position?

1 answer:

ycow [4]3 years ago

5 0

Answer:

1900 meters

Explanation:

30m/s x 30 second = 900 meters

+ 1000 meters starting position

= 1900meters

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Which of these black holes exerts the weakest tidal force on an object near its event horizon? Which of these black holes exerts

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Answer:

THA ANSWER IS B

Explanation:

YEH ITS B

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2 years ago

What is the wave speed of a wave that has a frequency of 250 Hz and a wavelength of 0.35 m?

azamat

Answer:

87.5 m/s

Explanation:

The speed of a wave is given by

$v=\lambda f$

where

v is the wave speed

$\lambda$ is the wavelength

f is the frequency

In this problem, we have

$f=250 Hz$ is the frequency

$\lambda=0.35 m$ is the wavelength

Substituting into the equation, we find

$v=(0.35 m)(250 Hz)=87.5 m/s$

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3 years ago

Two astronauts (each with mass 100 kg) are drifting together through space. They are connected to each other by a rope 5 m in le

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Answer:

1000 kgm²/s, 400 J

1000 kgm²/s, 1000 J

600 J

Explanation:

m = Mass of astronauts = 100 kg

d = Diameter

r = Radius = $\frac{d}{2}$

v = Velocity of astronauts = 2 m/s

Angular momentum of the system is given by

$L=mvr+mvr\\\Rightarrow L=2mvr\\\Rightarrow L=2\times 100\times 2\times 2.5\\\Rightarrow L=1000\ kgm^2/s$

The angular momentum of the system is 1000 kgm²/s

Rotational energy is given by

$K=I\omega^2\\\Rightarrow K=\frac{1}{2}(mr^2)\left(\frac{v}{r}\right)^2\\\Rightarrow K=mv^2\\\Rightarrow K=100\times 2^2\\\Rightarrow K=400\ J$

The rotational energy of the system is 400 J

There no external toque present so the initial and final angular momentum will be equal to the initial angular momentum 1000 kgm²/s

$L_i=L_f\\\Rightarrow 2mv_ir_i=2mv_fr_f\\\Rightarrow v_f=\frac{v_ir_i}{r_f}\\\Rightarrow v_f=\frac{2\times 2.5}{0.5}\\\Rightarrow v_f=10\ m/s$

Energy

$E_2=mv_f^2\\\Rightarrow E_2=100\times 10\\\Rightarrow E_2=1000\ J$

The new energy will be 1000 J

Work done will be the change in the kinetic energy

$W=E_2-E\\\Rightarrow W=1000-400\\\Rightarrow W=600\ J$

The work done is 600 J

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2 years ago

Which statement below concerning the photoelectric effect is true? View Available Hint(s) Which statement below concerning the p

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There is a threshold frequency for each metal, and only light of a frequency higher than this threshold causes electrons to be emitted from the metal surface.

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3 years ago

julsineya [31]

Answer:

Answer:

3 g/cm

Explanation:

Mass of stone = 30 g

Initial volume of cylinder = 50 cm

Increased volume = 60 cm

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= 3 g/ml as 1 ml = 1 cm

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Explanation:

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2 years ago