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3 years ago

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Physics

2 answers:

lesya692 [45]3 years ago

7 0

Answer:

John Dalton

Explanation:

Dalton's atomic theory was the foundation for a new understanding of chemical structures. He proposed that matter was constituted by indivisible and indestructible particles "atoms." He theorized that all atoms of a particular substance were equal, and the atoms of different substances had atoms of different sizes and masses.

He also proposed that all compounds of elements were combinations of elements but in a very precise ratio.

disa [49]3 years ago

6 0

Answer:John Dalton

Explanation:

He proposed the atomic theory in 1802 which states that

1.) All elements are made up of small,indivisible particles called atoms.

2.) Atoms can neither be created nor destroyed

3.) Atoms of the same element are alike in every aspect and differ from atoms of all other elements

4.)When atoms combine with other atoms they do so in simple ratios

5.) All chemical changes result from the combination or the separation of atoms.

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The angular speed of an automobile engine is increased at a constant rate from 1120 rev/min to 2560 rev/min in 13.8 s. (a) What

Neko [114]

Complete Question

The angular speed of an automobile engine is increased at a constant rate from 1120 rev/min to 2560 rev/min in 13.8 s.

(a) What is its angular acceleration in revolutions per minute-squared

(b) How many revolutions does the engine make during this 20 s interval?

rev

Answer:

$\alpha = 6261 \ rev/minutes^2$

$\theta = 613 \ revolutions$

Explanation:

From the question we are told that

The initial angular speed is $w_i = 1120 \ rev/minutes$

The angular speed after $t = 13.8 s = \frac{13.8}{60 } = 0.23 \ minutes$ is $w_f = 2560 \ rev/minutes$

The time for revolution considered is $t_r = 20 \ s = \frac{20}{60} = 0.333 \ minutes$

Generally the angular acceleration is mathematically represented as

$\alpha = \frac{w_f - w_i }{t}$

=> $\alpha = \frac{2560 - 1120 }{0.23}$

=> $\alpha = 6261 \ rev/minutes^2$

Generally the number of revolution made is $t_r = 20 \ s = \frac{20}{60} = 0.333 \ minutes$ is mathematically represented as

$\theta = \frac{1}{2} * (w_i + w_f)* t$

=> $\theta = \frac{1}{2} * (1120+ 2560 )* 0.333$

=> $\theta = 613 \ revolutions$

5 0

3 years ago

The power in an electrical current is given by the equation

Tcecarenko [31]

Answer:

P = VI

Explanation:

the power is equal to the current × voltage

6 0

2 years ago

Read 2 more answers

The nucleus contains protons and neutrons. Being positively charged, the protons repel each other. The nucleus should fly apart

Arte-miy333 [17]

this is due to the existence of other forces called the strong nuclear forces that overcomes the repulsion forces between the protons and keeps the nucleons holding to each other also there is a type of energy that is called the nuclear binding energy and this energy also works on binding the components of the nucleus together

6 0

3 years ago

A moving car skids to a stop with the wheels locked across a level roadway. Of the forces listed, identify which act on the car.

Vesnalui [34]

Answer:

Normal, Gravity, Friction, and Air Resistance.

Explanation:

When a moving car skid to stop and its wheels are locked across, then the following forces will be applied on the car:

Normal force: It will act counter to gravity that pushes an object against a surface and acts perpendicular to the contact surface.

Gravity: Gravity force acts in each and every object having mass and it can not be avoidable. So, the gravity force will also apply to the car and attract it to the earth's surface.

Friction: Friction is a force that acts opposite to the motion and stops or slows motion. Friction will be applied to the car that will oppose the motion of the car and stop it.

Air resistance: air resistance is defined as the forces exerted by air that acts opposite to the relative motion of an object. Air resistance will also be applied to the car when it will skid to stop as we are always surrounded by the air.

Hence, the correct answers are "Normal, Gravity, Friction, and Air Resistance."

4 0

3 years ago

6. Mr. Leppold jumps out of a plane with a parachute...before the chute opens,

polet [3.4K]

1) He has both potential and kinetic energy

2) Before the parachute opens, the potential energy decreases and the kinetic energy increases

Explanation:

The gravitational potential energy of a body is the energy possessed by the object due to its position in a gravitational field, and it is given by:

$PE=mgh$

where

m is the mass of the body

g is the acceleration of gravity

h is the height of the body above the ground

On the other hand, the kinetic energy of a body is the energy possessed by the body due to its motion; it is given by

$KE=\frac{1}{2}mv^2$

where

v is the speed of the object

Here Mr. Leppold has both potential and kinetic energy before opening the parachute, because:

- It is moving at a certain speed, so $v\neq 0$ , therefore he has kinetic energy

- He is at a certain height above the ground, $h\neq 0$ , therefore he has potential energy

The total mechanical energy of Mr.Leppold is the sum of the potential and the kinetic energy:

$E=PE+KE$

According to the law of conservation of energy, in absence of air resistance, this quantity remains constant.

During the fall, the height of Leppold decreases: this means that as $h$ decreases, the potential energy decreases too.

However, the total energy E must remain constant: therefore, this means that the kinetic energy KE must increase, and this occurs because the speed of Mr. Leppold increases as he falls.

Learn more about kinetic and potential energy:

brainly.com/question/6536722

brainly.com/question/1198647

brainly.com/question/10770261

#LearnwithBrainly

8 0

3 years ago