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3 years ago

A car travels at 40km/hr for 2 hours and at 55 km/hr for 2 hours. How far has the car traveled? What is its average velocity?

1 answer:

8 0

So if a car was moving 40km/hr, it means in 1 hour, the car will travel 40km. Since the car goes for 2 hours, the car will have traveled for 80 miles. Same.for the car going 55km/hr for 2 hours. 55 times 2 is 110km. 110 + 80 = 190km total. You can find the average velocity by by the distance traveled divided by how much time elapsed. so 190 divided by 4 is 47.5. So the distance traveled is 190km, and the average velocity is 47.5

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saul85 [17]

Answer:

Explanation:

Planets have different year lengths because it depends how far they revolve from a celestial body. Each planet has its own orbital period. Planets closer to the star will have a lower orbital period compared to the ones that lie far away from it.

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2 years ago

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The current through a 0.2-H inductor is i(t) = 10te–5t A. What is the energy stored in the inductor?

lakkis [162]

Answer:

E = 10t^2e^-10t Joules

Explanation:

Given that the current through a 0.2-H inductor is i(t) = 10te–5t A.

The energy E stored in the inductor can be expressed as

E = 1/2Ll^2

Substitutes the inductor L and the current I into the formula

E = 1/2 × 0.2 × ( 10te^-5t )^2

E = 0.1 × 100t^2e^-10t

E = 10t^2e^-10t Joules

Therefore, the energy stored in the inductor is 10t^2e^-10t Joules

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3 years ago

A 0.40 kg mass hangs on a spring with a spring constant of 12 N/m. The system oscillated with a constant amplitude of 12 cm. Wha

Vaselesa [24]

Answer:

The maximum acceleration of the system is 359.970 centimeters per square second.

Explanation:

The motion of the mass-spring system is represented by the following formula:

$x(t) = A\cdot \cos (\omega \cdot t + \phi)$

Where:

$x(t)$ - Position of the mass with respect to the equilibrium position, measured in centimeters.

$A$ - Amplitude of the mass-spring system, measured in centimeters.

$\omega$ - Angular frequency, measured in radians per second.

$t$ - Time, measured in seconds.

$\phi$ - Phase, measured in radians.

The acceleration experimented by the mass is obtained by deriving the position equation twice:

$a (t) = -\omega^{2}\cdot A \cdot \cos (\omega\cdot t + \phi)$

Where the maximum acceleration of the system is represented by $\omega^{2}\cdot A$ .

The natural frequency of the mass-spring system is:

$\omega = \sqrt{\frac{k}{m} }$

Where:

$k$ - Spring constant, measured in newtons per meter.

$m$ - Mass, measured in kilograms.

If $k = 12\,\frac{N}{m}$ and $m = 0.40\,kg$ , the natural frequency is:

$\omega = \sqrt{\frac{12\,\frac{N}{m} }{0.40\,kg} }$

$\omega \approx 5.477\,\frac{rad}{s}$

Lastly, the maximum acceleration of the system is:

$a_{max} = \left(5.477\,\frac{rad}{s})^{2}\cdot (12\,cm)$

$a_{max} = 359.970\,\frac{cm}{s^{2}}$

The maximum acceleration of the system is 359.970 centimeters per square second.

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3 years ago

Electricity costs 6 cents per kilowatt hour. In one month one home uses one megawatt hour of electricity. How much will the elec

Luda [366]

Answer:

Cost of 1000 kilowatt hour = 6000 cents

Explanation:

Given that

Electricity cost is 6 cents per kilowatt hour.

And we have to found out the cost for one megawatt hour

We know that

1 kilowatt = 1000 watt

1 megawatt = = 1000000 watt

1 megawatt = 1000 kilowatt

1 megawatt hour = 1000 kilowatt hour

Given that cost of 1 kilowatt hour = 6 cents

So the cost of 1000 kilowatt hour = 6 x 1000 cents

Cost of 1000 kilowatt hour = 6000 cents

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3 years ago

100 points!! word bank!

Novosadov [1.4K]

Answer:

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Explanation:

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3 years ago