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4 years ago

In what sense are telescopes like time machines?

1 answer:

8 0

<span>They allow us to see distant objects as they were long in the past.
-The further we look into space the further back we look in time.</span>

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If a proton and an electron are released when they are 4.00 x 10^-10 m apart, find the initial acceleration of each of them.

SVEN [57.7K]

Answer:

For proton

$a=8.8\times 10^{17}\ m/s^2$

For electron

$a=1.5\times 10^{21}\ m/s^2$

Explanation:

We know that

The mass of electron

$m=9.1\times 10^{-31}\ kg$

The mass of proton

$m=1.67\times 10^{-27}\ kg$

Charge on electron and proton

q₁=q₂=q

$q=1.6\times 10^{-19}\ C$

Electrostatics force

$F=K\dfrac{q_1q_2}{r^2}$

Now by putting the values

$F=9\times 10^9\times \dfrac{1.6\times 10^{-19}\times 1.6\times 10^{-19}}{(4\times 10^{-10})^2}$

$F=1.44\times 10^{-9}\ N$

For proton

F = m a

a =F/m

$a=\dfrac{1.4\times 10^{-9}}{1.67\times 10^{-27}}\ m/s^2$

$a=8.8\times 10^{17}\ m/s^2$

For electron

$a=\dfrac{1.4\times 10^{-9}}{9.1\times 10^{-31}}\ m/s^2$

$a=1.5\times 10^{21}\ m/s^2$

5 0

3 years ago

Read 2 more answers

Select the higher harmonics of a string fixed at both ends that has a fundamental frequency of 80 Hz.

DedPeter [7]

It is defined that a string that is in its two ends, its fundamental frequency and its subsequent frequencies are the product of the whole depending on the number of the harmonic. In other words, harmonics (higher) define the subsequent frequencies under the functions 2f, 3f, 4f, 5f, etc.

Therefore we have that the higher harmonics would be:

1 x 80 Hz = 80 Hz (1st harmonic and Fundalmental Frequency)

2 x 80Hz = 160Hz (2nd harmonic)

3 x 80Hz = 240Hz (3rd harmonic)

4 x 80Hz = 320Hz (4th harmonic)

5 x 80Hz = 400Hz (5th harmonic)

Hence, the frequencies 160Hz and 240Hz are the two higher harmonics of string with a fundamental frequency of 80Hz.

6 0

3 years ago

Which example best represents translational kinetic energy? A plucked string guitar. The moving blades of a ceiling fan. A spinn

MrRa [10]

Answer:

The answer is e the apple one

Explanation:

5 0

3 years ago

Read 2 more answers

Eric has a mass of 80 kgkg. He is standing on a scale in an elevator that is accelerating downward at 1.7 m/s2m/s2. What is the

kolezko [41]

Answer:

The answer will be 936 N.

Explanation:

Given that

m = 80 kg

Acceleration of the elevator , a= 1.7 m/s² ( upward)

The gravity force on the mass = m g

The reading on the scale = F N

Now by applying the Newton's second law

F - m g = ma

F= m g + m a

F= m ( g +a )

F= 80 ( 10 + 1.7 ) N ( take g= 10 m/s²)

F=80 x 11.7 N

F= 936 N

Therefore the reading on the scale will be 936 N.

The answer will be 936 N.

5 0

3 years ago

A bullet of mass 120g is fired horizontally into a fixed wooden block with a speed of 20m\s. The bullet is brought to rest in a

prohojiy [21]

Answer:

1) F = 24 N

2) Distance = 1 m

Explanation:

We are given;

Mass; m = 120 g = 0.12 kg

Initial velocity; u = 20 m/s

Final velocity; v = 0 m/s since it came to rest.

Time; t = 0.1 s

We can calculate acceleration from Newton's first equation of motion;

a = (v - u)/t

a = (0 - 20)/0.1

a = -200 m/s²

1) magnitude of the resistance will be;

F = ma

F = 0.12 × (-200)

F = -24 N

Since, we are dealing with the magnitude, we will take the absolute value. Thus, F = 24 N

2) To find the distance moved by the bullet, we know that;

Distance = Average speed × time

Thus;

Distance = ((v + u)/2) × t

Distance = ((0 + 20)/2) × 0.1

Distance = 1 m

4 0

3 years ago