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adelina 88 [10]
3 years ago
5

In which one of the following circumstances could mechanical energy not possibly be conserved, even if friction and air resistan

ce are absent?
A car moves down a hill, its velocity continually increasing alongthe way.
A car moves up a hill at a constant velocity.
A car moves along level ground at a constant velocity.
A car moves up a hill, its velocity continually decreasing alongthe way.
Physics
1 answer:
qwelly [4]3 years ago
5 0

Answer:

A car moves up a hill at a constant velocity

Explanation:

Since the velocity is constant, the speed is also constant and so is the kinetic energy. However, total mechanical energy is sum of gravitational potential energy and kinetic energy, and the car is moving up the hill so its potential energy rises.

Thus, in the circumstances described the mechanical energy cannot be conserved.

The correct answer is A car moving up the hill with constant velocity.

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What ocean resource may be harvested by vacuuming or trawling?
juin [17]

Answer:

B, fish.

Fish may be harvested by vacuuming or trawling.

Add on:

hope this helped at all.

3 0
3 years ago
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Which term refers to a variable that a scientist adjusts during an experiment?
azamat

Answer:

it’s c

Explanation:

5 0
3 years ago
A large lightning bolt is observed to have a 19500 A current and move 36 C of charge. What was its duration?
Lynna [10]

Answer:

Its duration is 1.85*10⁻³ s or 1.85 ms

Explanation:

The intensity of electric current I is defined as the amount of electric charge Q (measured in Coulombs) that passes through a section of a conductor in each unit of time. The letter I is used to name the Intensity and its unit is the Ampere (A).

The intensity of electric current is expressed as:

I=\frac{Q}{t}

where:

I: Intensity expressed in Amps (A)

Q: Electric charge expressed in Coulombs (C)

t: Time expressed in seconds (s)

Being:

  • I= 19500 A
  • Q=36 C
  • t=?

Replacing:

19500 A=\frac{36 C}{t}

Solving:

19500 A*t= 36 C

t=\frac{36 C}{19500 A}

t= 1.85*10⁻³ s= 1.85 ms (being 1 s= 1,000 ms)

<u><em>Its duration is 1.85*10⁻³ s or 1.85 ms</em></u>

8 0
3 years ago
Astronomers have observed a small, massive object at the center of our Milky Way Galaxy. A ring of material orbits this massive
Setler [38]

Answer:

The mass of the massive object at the center of the Milky Way galaxy is 3.44\times10^{37}\ Kg

Explanation:

Given that,

Diameter = 10 light year

Orbital speed = 180 km/s

Suppose determine the mass of the massive object at the center of the Milky Way galaxy.

Take the distance of one light year to be 9.461×10¹⁵ m. I was able to get this it is 4.26×10³⁷ kg.

We need to calculate the radius of the orbit

Using formula of radius

r=\dfrac{d}{2}

r=\dfrac{15\times9.461\times10^{15}}{2}

r=7.09\times10^{16}\ m

We need to calculate the mass of the massive object at the center of the Milky Way galaxy

Using formula of mass

M=\dfrac{v^2r}{G}

Put the value into the formula

M=\dfrac{(180\times10^3)^2\times7.09\times10^{16}}{6.67\times10^{-11}}

M=3.44\times10^{37}\ Kg

Hence, The mass of the massive object at the center of the Milky Way galaxy is 3.44\times10^{37}\ Kg

5 0
3 years ago
Physical Science Lesson 4 unit 2 questions, I need the answers
neonofarm [45]
I know I'm a bit late but just in case you still need some of the answers.

1: Oxygen
2: Change in shape
3: Water breaking down into hydrogen and oxygen
4: I think it's Milk but I might be wrong.

I might be wrong about some of them, sorry it's not much.

7 0
3 years ago
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