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3 years ago

At 2.5 seconds, the helicopter has a kinetic energy of 20J. What is its mechanical energy at that time?

1 answer:

3 0

The mechanical energy of an object is equivalent to the sum of its potential and kinetic energy. If the helicopter is grounded, then its mechanical energy will be 20 J. If it is in the air, then its potential energy will be calculated using:P.E = mghAnd then added to the kinetic energy to obtain mechanical energy.

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A technique in which people use machines to learn how to control their bodies is known as __________.

Debora [2.8K]

Answer:

The technique in which people use machines to learn how to control their bodies is known as D, Biofeedback.

Explanation:

Biofeedback is a variety of different machines that help people learn how to control their bodies depending on their specific needs, varying from things like scalp sensors, electrocardiographs, electromyographs and more.

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4 years ago

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Which explanation is based on scientific evidence?

Yuki888 [10]

Answer:

Scientific evidence is evidence that serves to either support or counter a scientific theory or hypothesis. Such evidence is expected to be empirical evidence and interpretable in accordance with scientific method.

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3 years ago

For a moon orbiting its planet, rp is the shortest distance between the moon and its planet andra is the longest distance betwee

Natasha2012 [34]

Answer: D. 0.57

Explanation:

The formula to calculate the eccentricity $e$ of an ellipse is (assuming the moon's orbit in the shape of an ellipse):

$e=\frac{r_{a}-r_{p}}{r_{a}+r_{p}}$

Where:

$r_{a}$ is the apoapsis (the longest distance between the moon and its planet)

$r_{p}=0.27 r_{a}$ is the periapsis (the shortest distance between the moon and its planet)

Then:

$e=\frac{r_{a}-0.27 r_{a}}{r_{a}+0.27 r_{a}}$

$e=\frac{0.73 r_{a}}{1.27 r_{a}}$

$e=0.57$ This is the moon's orbital eccentricity

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3 years ago

Which of the following does not change the resistance of a wire?

ivanzaharov [21]

Number 1. The medium around the wire

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3 years ago

How much heat is needed to change 1.25 kg of steak at 100°C to water at 100°C?

cricket20 [7]

The heat required to change 1.25 kg of steak is 2825 kJ /kg.

<u>Explanation</u>:

Given, mass m = 1.25 kg, Temperature t = 100 degree celsius

To calculate the heat required,

Q = m $\times$ L

where m represents the mass in kg,

L represents the heat of vaporization.

When a material in the liquid state is given energy, it changes its phase from liquid to vapor and the energy absorbed in this process is called heat of the vaporization. The heat of vaporization of the water is about 2260 kJ/kg.

Q = 1.25 $\times$ 2260

Q = 2825 kJ /kg.

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4 years ago