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3 years ago

Energy conservation

Physics

1 answer:

balandron [24]3 years ago

7 0

Answer:

7.328m/s

Explanation:

Given parameters:

height of table = 0.68m

final velocity of the ball = 6m/s

Unknown:

Initial velocity of ball = ?

Solution:

To solve this problem, we are going to employ the appropriate motion equation.

We must understand that this fall occurs in the presence of gravity;

V = U + 2gH

Where;

V is the final velocity

U is the initial velocity

g is the acceleration due to gravity

H is the height of the pool table

Since U is the unknown, let us make it the subject of the expression;

U = V - 2gH

U = 6 - (2 x 9.8 x 0.68) = 7.328m/s(deceleration)

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A cart of mass m = 0.12 kg moves with a speed v = 0.45 m/s on a frictionless air track and collides with an identical cart that

lina2011 [118]

Answer:

0.006075Joules

Explanation:

The final kinetic energy of the system is expressed as;

KE = 1/2(m1+m2)v²

m1 and m2 are the masses of the two bodies

v is the final velocity of the bodies after collision

get the final velocity using the law of conservation of momentum

m1u1 + m2u2 = (m1+m2)v

0.12(0.45) + 0/12(0) = (0.12+0.12)v

0.054 = 0.24v

v = 0.054/0.24

v = 0.225m/s

Get the final kinetic energy;

KE = 1/2(m1+m2)v

KE = 1/2(0.12+0.12)(0.225)²

KE = 1/2(0.24)(0.050625)

KE = 0.12*0.050625

KE = 0.006075Joules

Hence the final kinetic energy of the system is 0.006075Joules

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3 years ago

Please tell me if this is Newton's first law, second, or third law of motion. There can be more than one of the same answer very

AfilCa [17]

Answer: Hope This Helps!

Explanation:

1: Newton’s first law of motion can explain how a magician pulls a tablecloth from underneath the dishes. A negligible horizontal force is applied during the process. As per Newton’s first law of motion, the dishes and glasses remain in their state of motion (rest); as a result, they remain undisturbed.

2: Newton's First Law of Motion is defined as "An object at rest and an object in motion will stay in motion with the same speed and in the same direction unless acted upon by an unbalanced force."In soccer, when the soccer ball is in the soccer field and it is not moving, that means that it is at rest and there is no force acting upon it. When there is a person that is ready to play soccer and wants to kick the ball and play, then the unbalanced force would be the power from the person's foot.

3: Newtons third law can explain, as the cannonball is pushed forwards by the expanding high-pressure gases created by the exploding gunpowder, it pushes back on these gases. The gases push back on the cannon itself, causing it to roll backwards. Alternative answer: the cannon pushes forward on the cannonball. the reaction force is the cannonball pushing backwards on the cannon.

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3 years ago

What is E of a hydrogen atom in the 3p state?

notsponge [240]

Answer:

E=-1.51 eV.

$L=\hbar\sqrt{2}$

Explanation:

The nth level energy of a hydrogen atom is defined by the formula,

$E_{n}=-\frac{13.6}{n^{2} }$

Given in the question, the hydrogen atom is in the 3p state.

Then energy of n=3 state is,

$E_{n}=-\frac{13.6}{(3)^{2} }\\E_{n}=-1.51eV$

Therefore, energy of the hydrogen atom in the 3p state is -1.51 eV.

Now, the value of L can be calculated as,

$L=\hbar\sqrt{l(l+1)}$

For 3p state, l=1

$L=\hbar\sqrt{1(1+1)}\\L=\hbar\sqrt{2}$

Therefore, the value of L of a hydrogen atom in 3p state is $L=\hbar\sqrt{2}$ .

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3 years ago

What causes the particles within the nucleus of an atom to bond together? Question 12 options: electromagnetism gravity weak nuc

monitta

Answer:

Strong nuclear force

Explanation:

The particles in the atom's nucleus bond together because there is a strong nuclear force between the protons and neutrons that attracts them to each other and binds together the nucleus.

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3 years ago

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Calculate the energy used by a radio of power 30W in 1 minute.

Alekssandra [29.7K]

Answer:

1.8kJ

Explanation:

Formula :

Energy used = Power x time

===============================================================

Given :

⇒ Power = 30 W

⇒ Time = 1 minute = 60 seconds

=============================================================

Solving :

⇒ Energy used = 30 W × 60 s

⇒ Energy used = 1,800 J

⇒ Energy used = 1.8kJ

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2 years ago

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