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2 years ago

What it means to say that energy is conserved as a ball fall towards ground

1 answer:

5 0

Mechanical energy = Potential Energy + Kinetic Energy

if there is no friction, M.E. is conserved
as a ball falls, it is losing height. (P.E.=mgh , therefore P.E. will decrease)

the potential energy is transformed into kinetic energy which equals 1/2MV^2.

the increase in K.E. equals the decrease in P.E.

and the sum of both equals M.E.

thus mechanical energy is conserved.

hope this helps you.

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mixas84 [53]

The answer is A. Commensalism. Commensalism, in ecology, is a class of relationships between two organisms where one organism benefits from the other without affecting it. This was the briefest answer from Wiki. Hope it helps, and sorry I'm late.

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3 years ago

According to the rayleigh criterion, what is the shortest object we could resolve at the 25.0 cm near point with light of wavele

Blizzard [7]

Answer:

$6.71 *10^{-5}$ rad

Explanation:

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∅ = $6.71 *10^{-5}$ rad

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2 years ago

Help with velocity math pls help asap

pychu [463]

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2 years ago

How did scientists discover the Earth had a liquid outer core and solid inner core?

viktelen [127]

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6 0

3 years ago

A boy throws a ball of mass 0.22 kg straight upward with an initial speed of 29 m/s. When the ball returns to the boy, its speed

maksim [4K]

Answer:

The work is -67.76 J

Explanation:

The law of conservation of energy is considered one of one of the fundamental laws of physics and states that the total energy of an isolated system remains constant. except when it is transformed into other types of energy.

This is summed up in the principle that energy can neither be created nor destroyed in the universe, only transformed into other forms of energy.

In this case you must calculate the loss of kinetic energy. This loss is actually the work done against the resistive force in the air. Friction is the only force other than gravity that acts on the ball.

So, the loss of kinetic energy is $\frac{1}{2} *m*(vf^{2} -vi^{2} )$

You know:

mass=m=0.22 kg
Initial velocity of the ball: $vi= 29 \frac{m}{s}$

Final velocity of the ball: $vf= 15 \frac{m}{s}$

Replacing:

$\frac{1}{2} *0.22 kg*(15^{2} -29^{2} )$ = -67.76 J

Friction work is always negative because friction is always against displacement.

The work is -67.76 J

5 0

3 years ago