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2 years ago

Dźwig podniósł kontener o masie m = 80 kg na wysokość h = 10 m. Pierwsze 5 m kontener przebył z przy-

Physics

1 answer:

Nady [450]2 years ago

7 0

Answer:

a) W_total = 8240 J , b) W₁ / W₂ = 1.1

Explanation:

In this exercise you are asked to calculate the work that is defined by

W = F. dy

As the container is rising and the force is vertical the scalar product is reduced to the algebraic product.

W = F dy = F Δy

let's apply this formula to our case

a) Let's use Newton's second law to calculate the force in the first y = 5 m

F - W = m a

W = mg

F = m (a + g)

F = 80 (1 + 9.8)

F = 864 N

The work of this force we will call it W1

We look for the force for the final 5 m, since the speed is constant the force must be equal to the weight (a = 0)

F₂ - W = 0

F₂ = W

F₂ = 80 9.8

F₂ = 784 N

The work of this fura we will call them W2

The total work is

W_total = W₁ + W₂

W_total = (F + F₂) y

W_total = (864 + 784) 5

W_total = 8240 J

b) To find the relationship between work with relate (W1) and work with constant speed (W2), let's use

W₁ / W₂ = F y / F₂ y

W₁ / W₂ = 864/784

W₁ / W₂ = 1.1

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Lucille is finding it difficult to play soccer after school. Her doctor thinks that her cells might not be getting enough oxygen

Bad White [126]

Explanation:

Lucile

Lucile cells needs a huge abundance of glucose and oxygen supply in order for her body to function properly and participate in a soccer game.

Playing a soccer game is energy demanding. The body's energy supply is met by the metabolism of glucose in cells using oxygen.

The problem with Lucille's respiratory and circulatory system can make it difficult for her to take part in soccer game because the needed energy would not be available for her to participate in the game.

Respiratory system is saddled with the responsibility of bringing enough oxygen to body system through gaseous exchange and metabolism.
The circulatory system carries the oxygen to the different body cells to where they are need. It also takes the deoxygenated blood to where they can get oxygenated.
We can clearly see that if respiratory and circulatory systems are not functioning well, Lucille's cells will not be able to furnish her with the much needed energy.

Ezra

Ezra needs energy to play basketball well. The energy is produced via the glucose in the starch and the oxygen from breathing.

When starch is broken down, glucose is produced.

How it works;

The digestive, circulatory and respiratory systems are all important here. They ensure that Ezra gets the needed energy from the food he is eating. Proteins also have the capability of producing energy when there is shortage of starch in the body.

Ezra's digestive system through a couple of processes releases glucose from the food he eats especially the bread in the sandwich.

The glucose is stored in the body and made available for use when in need.

The glucose is used to produce energy.

When Ezra breathes, the circulatory system ensures gaseous exchange with the surroundings. Oxygen rich blood is taken the cells where they combine with glucose for their metabolic actions. Oxygen deficient bloods are carried away.

In the cell, a special apparatus called the mitochondria combines glucose with oxygen and energy is liberated. The energy is used by Ezra to run while playing basketball

learn more:

Cellular respiration brainly.com/question/3447259

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7 0

2 years ago

You slip a wrench over a bolt. Taking the origin at the bolt, the other end of the wrench is at x=18cm, y=5.5cm. You apply a for

mart [117]

Answer:

The torque on the wrench is 4.188 Nm

Explanation:

Let r = xi + yj where is the distance of the applied force to the origin.

Since x = 18 cm = 0.18 cm and y = 5.5 cm = 0.055 cm,

r = 0.18i + 0.055j

The applied force f = 88i - 23j

The torque τ = r × F

So, τ = r × F = (0.18i + 0.055j) × (88i - 23j) = 0.18i × 88i + 0.18i × -23j + 0.055j × 88i + 0.055j × -23j

= (0.18 × 88)i × i + (0.18 × -23)i × j + (0.055 × 88)j × i + (0.055 × -22)j × j

= (0.18 × 88) × 0 + (0.18 × -23) × k + (0.055 × 88) × (-k) + (0.055 × -22) × 0 since i × i = 0, j × j = 0, i × j = k and j × i = -k

= 0 - 4.14k + 0.0484(-k) + 0

= -4.14k - 0.0484k

= -4.1884k Nm

≅ -4.188k Nm

So, the torque on the wrench is 4.188 Nm

8 0

2 years ago

An object is thrown with an initial speed v near the surface of Earth. Assume that air resistance is negligible and the gravitat

IgorLugansk [536]

Answer:

E. downward and constant

Explanation:

Freefall is a special case of motion with constant acceleration because the acceleration due to gravity is always constant and downward. This is true even when an object is thrown upward or has zero velocity.

For example, when a ball is thrown up in the air, the ball's velocity is initially upward. Since gravity pulls the object toward the earth with a constant acceleration ggg, the magnitude of velocity decreases as the ball approaches maximum height. At the highest point in its trajectory, the ball has zero velocity, and the magnitude of velocity increases again as the ball falls back toward the earth.

3 0

2 years ago

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An organ pipe is tuned to exactly 384 Hz when the temperature in the room is 20°C. Later, when the air has warmed up to 25°C, th

maksim [4K]

Answer: A. Greater than 384 Hz

Explanation:

The velocity of sound is directly related to the temperature rather it is directly proportional meaning if the temperature decreases the velocity decreases and if temperature increases the velocity increases.

Now, we are given that temperature has risen from 20°C to 25°C meaning it has increases. So it implies that velocity must also increase.

Also, the velocity for organ pipe is directly proportional to its frequency. Now if velocity increases frequency must also increase. In this case, the original frequency is 384 Hz. Now increasing the temperature resulted in increase in velocity and thus increase in frequency.

So option a is correct. i.e. now frequency will be greater than 384 Hz.

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2 years ago

The diagram shows a heat engine. In which area of the diagram is unusable thermal energy detected?

Marat540 [252]

Nope, I disagree with the former answer. The answer is definitely Z. <u>W area</u> (boxed with red outline) is represented as the hot reservoir while <u>Z area</u> is the cold reservoir (boxed with blue outline). X area is the heat engine itself and Y area is the work produced from thermal energy from hot reservoir. Typically, all heat engines lose some heat to the environment (based from the second law of thermodynamics) that is symbolically illustrated by the lost energy in the cold reservoir. This lost thermal energy is basically the unusable thermal energy. The higher thermal energy lost, the less efficient your heat engine is.

7 0

2 years ago

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