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3 years ago

The first law of Thermodynamics is another way to describe the law of conservation of Energy. It states that:

Physics

1 answer:

nikitadnepr [17]3 years ago

6 0

Answer:

C. The change of internal energy of a system is the sum of work and heat spent on it.

Explanation:

The law of conservation of Energy states that energy cannot be destroyed but can only be converted or transformed from one form to another. Therefore, the sum of the initial kinetic energy and potential energy is equal to the sum of the final kinetic energy and potential energy.

Mathematically, it is given by the formula;

Ki + Ui = Kf + Uf .......equation 1

Where;

Ki and Kf are the initial and final kinetic energy respectively.

Ui and Uf are the initial and final potential energy respectively.

The law of conservation of Energy is another way to describe the law of Thermodynamics. It states that the change of internal energy of a system is the sum of work and heat spent on it.

Mathematically, it is given by the formula;

ΔU = Q − W

Where;

ΔU represents the change in internal energy of a system.

Q represents the net heat transfer in and out of the system.

W represents the sum of work (net work) done on or by the system.

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An elevator supported by a single cable descends a shaft at a constant speed. The only forces acting on the elevator are the ten

VikaD [51]

Answer:

C. The net work done by the two forces is zero joules.

Explanation:

Work (W) is defined as the product of force F) by the distance (d)the body travels due to this force.

W= F*d Formula ( 1)

The work is positive (W+) if the force has the same direction of movement of the object.

The work is negative (W-) if the force has the opposite direction of the movement of the object.

The component of the force that performs work must be parallel to the displacement.

Calculation of the forces

We apply Newton's second law:

∑F = m*a

∑F : algebraic sum of the forces in Newton (N)

m : mass in kilograms (kg)

a : acceleration in meters over second square (m/s²)

∑F = m*a

a = 0 because the elevator moves at constant speed.

∑F=0

T-W = 0

T = W

Calculation of work done by the forces

W₁ : work done by the gravity= (+ W*d ) J

W₂ : work done by the tension force=( -T*d) J

Net work done by the two forces(W₁-W₂):

W₁= W₂ .because T = W

W₁-W₂ =0

3 0

3 years ago

2. This diagram represents a top-down view of an experiment on a table. The 250 g and 100 g masses are falling and are pulling t

Rasek [7]

Answer:

According to the data given in the question, experiment on table two pulling and falling masses are arranged in the fig. 250 g is pulling right side and 100 g pulling down. The gravitational force is common to both the masses, so we cannot say that the block moves towards heavier mass, also the block does not move towards the lighter mass.

Obviously, the effect of heavier mass of 250 g is more on the block, so the block moves towards right bottom corner. i.e., diagonally between two masses

please find the attachment.