True or false: (a) the induced emf in a circuit is proportional to the magnetic flux through the circuit.

Umnica [9.8K]

Answer:

Potential energy is the energy that exists by virtue of the relative positions (configurations) of the objects within a physical system.

This form of energy has the potential to change the state of other objects around it, for example, the configuration or motion.

Various forms of energy can be grouped as potential energy.

Each of these forms is associated with a particular kind of force acting in conjunction with some physical property of matter (such as mass, charge, elasticity, temperature etc).

For example, gravitational potential energy is associated with the gravitational force acting on object's mass; elastic potential energy with the elastic force (ultimately electromagnetic force) acting on the elasticity of a deformed object; electrical potential energy with the coulombic force; strong nuclear force or weak nuclear force acting on the electric charge on the object; chemical potential energy, with the chemical potential of a particular atomic or molecular configuration acting on the atomic/molecular structure of the chemical substance that constitutes the object; thermal potential energy with the electromagnetic force in conjunction with the temperature of the object.

For an example of gravitational potential energy, consider a book placed on top of a table.

To raise the book from the floor to the table, work must be done, and energy supplied. (If the book is lifted by a person then this is provided by the chemical energy obtained from that person's food and then stored in the chemicals of the body.) Assuming perfect efficiency (no energy losses), the energy supplied to lift the book is exactly the same as the increase in the book's gravitational potential energy.

The book's potential energy can be released by knocking it off the table.

As the book falls, its potential energy is converted to kinetic energy.

When the book hits the floor this kinetic energy is converted into heat and sound by the impact.

Explanation:

4 0

3 years ago

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Two bumper cars in an amusement park ride collide elastically as one approaches the other directly fromthe rear. Car A has a mas

zubka84 [21]

Answer:

a) The velocity of car B after the collision is 4.45 m/s.

The velocity of car A after the collision is 3.65 m/s.

b) The change of momentum of car A is - 370.45 kg · m/s

The change of momentum of car B is 370.45 kg · m/s

Explanation:

Hi there!

Since the cars collide elastically, the momentum and kinetic energy of the system do not change after the collision.

The momentum of the system is calculated adding the momenta of each car:

initial momentum = final momentum

mA · vA + mB · vB = mA · vA´ + mB · vB´

Where:

mA = mass of car A

vA = initial velocity of car A

mB = mass of car B

vB = initial velocity of car B

vA´= final velocity of car A

vB´ = final velocity of car B

Let´s replace with the data we have and solve the equation for vA´:

mA · vA + mB · vB = mA · vA´ + mB · vB´

435 kg · 4.50 m/s + 495 kg · 3.70 m/s = 435 kg · vA´ + 495 kg · vB´

3789 kg · m/s = 435 kg · vA´ + 495 kg · vB´

3789 kg · m/s - 495 kg · vB´ = 435 kg · vA´

(3789 kg · m/s - 495 kg · vB´)/435 kg = vA´

Let´s write this expression without units for a bit more clarity:

vA´= (3789 - 495 vB´)/435

The kinetic energy of the system is also conserved, then, the initial kinetic energy is equal to the final kinetic energy:

initial kinetic energy of the system = final kinetic energy of the system

1/2 · mA · vA² + 1/2 · mB · vB² = 1/2 · mA · (vA´)² + 1/2 · mB · (vB´)²

Replacing with the data:

initial kinetic energy = 1/2 · 435 kg · (4.50 m/s)² + 1/2 · 495 kg · (3.70)²

initial kinetic energy = 7792.65 kg · m²/s²

7792.65 kg · m²/s² = 1/2 · 435 kg · (vA´)² + 1/2 · 495 kg · (vB´)²

multiply by 2 both sides of the equation:

15585.3 kg · m²/s² = 435 kg · (vA´)² + 495 kg · (vB´)²

Let´s replace vA´ = (3789 - 495 vB´)/435

I will omit units for clarity in the calculation:

15585.3 = 435 · (vA´)² + 495 · (vB´)²

15585.3 = 435 · (3789 - 495 vB´)²/ 435² + 495 (vB´)²

15585.3 = (3789² - 3751110 vB´ + 245025 vB²) / 435 + 495 (vB´)²

multiply both sides of the equation by 435:

6779605.5 = 3789² - 3751110 vB´ + 245025 vB² + 215325 vB´²

0 = -6779605.5 + 3789² - 3751110 vB´ + 460350 vB´²

0 = 7576915.5 - 3751110 vB´ + 460350 vB´²

Solving the quadratic equation:

vB´ = 4.45 m/s

vB´ = 3.70 m/s (the initial velocity)

a) The velocity of car B after the collision is 4.45 m/s

The velocity of car A will be teh following:

vA´= (3789 - 495 vB´)/435

vA´= (3789 - 495 (4.45 m/s))/435

vA´ = 3.65 m/s

The velocity of car A after the collision is 3.65 m/s

b) The change of momentum of each car is calculated as the difference between its final momentum and its initial momentum:

ΔpA = final momentum of car A - initial momentum of car A

ΔpA = mA · vA´ - mA · vA

ΔpA = mA (vA´ - vA)

ΔpA = 435 kg (3.648387097 m/s - 4.50 m/s) (I have used the value of vA´ without rounding).

ΔpA = - 370.45 kg · m/s

The change of momentum of car A is - 370.45 kg · m/s

ΔpB = mB (vB´ - vB)

ΔpB = 495 kg (4.448387097 m/s - 3.70 m/s) (I have used the value of vB´ without rounding).

ΔpB = 370.45 kg · m/s

The change of momentum of car B is 370.45 kg · m/s

I have used the values of the final velocities without rounding so we can notice that the change of momentum of both cars is equal but of opposite sign.

7 0

3 years ago

A wave has a wavelength of 5mm and a frequency of 10 hertz what is its speed? answer: units:

gayaneshka [121]

Speed=wavelength×frequency
speed= 0.005m × 10 Hz = 0.05m/s

3 0

3 years ago

¿Qué tipo de nutrientes proporcionan energía a nuestro organismo?

kow [346]

Answer:

The correct answer is: macronutrients.

Explanation:

Nutrients are chemical substances found in food that, when consumed, allow the development, maintenance and functioning of our body.

Every time you eat a food, your body assimilates, transforms and takes advantage of its nutrients in order to live.

No single food can provide us with all the nutrients that the body needs. Only a healthy, varied and balanced diet will do it.

Types of nutrients :

Nutrients can be essential (the body cannot synthesize them on its own and we must acquire them through food) or non-essential (our body produces them from other components). According to their proportion they are divided into :

macronutrients: they occupy most of the food and are consumed in grams. They are carbohydrates or carbohydrates (sugar, vegetables, fruit, cereals, etc); proteins (meat, fish, eggs, milk, etc.), fats or lipids (oils, seeds, nuts, milk and derivatives).

micronutrients: we take them in micrograms. In this group we find vitamins and minerals. The main source is fruits and vegetables, although we also get them from most foods.

Water is another essential nutrient, without which we could not live and that helps all the physiological processes of the body to take place.

Nutrients are classified into:

-Energy nutrients: provide the energy the body needs to function. Macronutrients are the main source of energy. Among these are carbohydrates and fats and to a lesser extent proteins.

-Plastic nutrients: involved in the construction of body structures, maintenance and repair of tissues. Proteins and mineral salts belong to this group.

-Regulatory nutrients: participate in the body's regulatory processes. They are vitamins and minerals.

7 0

3 years ago

What is an astronomical unit?

Pie

<span>the average distance between the Earth and the Sun</span>

5 0

4 years ago

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