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3 years ago

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Marc was told his dinner would be ready at 18:00. He left his house at 12:00 and travelled in his car at an average speed of 45m

ph to his mum's house 300 miles away. Did Marc make it home in time for dinner

1 answer:

Tema [17]3 years ago

5 0

Answer:

No

Explanation:

<u>No, Marc did not make it on time for dinner.</u>

The time duration between 12:00 and 18:00 is 6 hours.

Total distance that needs to be covered from his house to his mum's house and back = 300 miles x 2 = 600 miles

Time that would be needed to cover 600 miles to his mum's house at an average speed of 45 mph = distance/speed

= 600/45

= 13.33 hours

<em>The required time to cover the distance by Marc is approximately 13.33 hours. If he leaves the house by 12:00, he will definitely not get back 6 hours after. Hence, he could not have made it for dinner.</em>

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Answer:

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Explanation:

Given that :

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Making the spring constant $k_{eq}$ the subject of the formula; we have:

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Substituting our given values, we have:

$k_{eq} = \frac{2*80}{0.180^2}$

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Be sure to answer all parts. Compare the wavelengths of an electron (mass = 9.11 × 10−31 kg) and a proton (mass = 1.67 × 10−27 k

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Explanation:

Given that,

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Mass of the electron, $m_e=9.11\times 10^{-31}\ kg$

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$\lambda_e=1.09\times 10^{-10}\ m$

The wavelength of the proton is given by :

$\lambda_p=\dfrac{h}{m_p v}$

$\lambda_p=\dfrac{6.63\times 10^{-34}}{1.67\times 10^{-27}\times 6.66\times 10^6}$

$\lambda_p=5.96\times 10^{-14}\ m$

(b) Kinetic energy, $K=1.71\times 10^{-15}\ J$

The relation between the kinetic energy and the wavelength is given by :

$\lambda_e=\dfrac{h}{\sqrt{2m_eK}}$

$\lambda_e=\dfrac{6.63\times 10^{-34}}{\sqrt{2\times 9.11\times 10^{-31}\times 1.71\times 10^{-15}}}$

$\lambda_e=1.18\times 10^{-11}\ m$

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$\lambda_p=\dfrac{6.63\times 10^{-34}}{\sqrt{2\times 1.67\times 10^{-27}\times 1.71\times 10^{-15}}}$

$\lambda_p=2.77\times 10^{-13}\ m$

Hence, this is the required solution.

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A 2-kW electric heater takes 15 min to boil a quantity of water. If this is done once a day and power costs 10 cents per kWh, wh

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Answer:

<h2> $1.50</h2>

Explanation:

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We are expected to compute the cost of operating the heater for 30 days

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<u><em>Hence it will cost $1.50 for 30 days operation</em></u>

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Explanation:

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Artemon [7]

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Explanation: To find the answer we need to know more about the Newton's law of gravitation.

<h3>What is Newton's law of gravitation?</h3>

Gravitation is the force of attraction between any two bodies.
Every body in the universe attracts every other body with a force.
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Mathematically we can expressed it as,

$F=\frac{GMm}{r^2} \\where, G=6.67*10^-11Nm^2kg^-2$

<h3>How to solve the problem?</h3>

Here, we have given with the data's,

$M=8.22*10^9kg\\m=1.38*10^8 kg\\r=1.43*10^3m$

Thus, the force of attraction between these two bodies will be,

$F=6.67*10^-11*\frac{8.22*10^9*1.38*10^8}{1.43*10^3} =52.9kN$

Thus, if two celestial objects are in space: one with a mass of 8.22 x 109 kg and one with a mass of 1.38 x 108 kg and, If they are separated by a distance of 1.43 km, then, the magnitude of the force of attraction (in newtons) between the objects will be 52.9kN.

Learn more about the Newton's law of gravitation here:

brainly.com/question/28045318

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