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2 years ago

Tragically, the united states lost astronauts in accidents involvin

Physics

2 answers:

Valentin [98]2 years ago

8 0

Answer:

challenger and Columbia

Explanation:

sweet-ann [11.9K]2 years ago

7 0

The quest to put Americans on the moon before the Soviets do. During the Space Race, a couple of astronauts went up into space only to be tragically killed in an explosion.

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1. A 100-kg crate is pulled across a warehouse floor using a rope with a force of 250 N at an angle of 45o from the horizontal.

harkovskaia [24]

Answer:

(a) The net force is 80.394 N

The acceleration of the crate is 0.804 m/s²

(b) the final velocity of the crate is 5.02 m/s

Explanation:

Given;

mass of the crate, m = 100 kg

applied force, F = 250 N

angle of inclination, θ = 45°

coefficient of friction, μ = 0.12

Applied force in y-direction, $F_y = Fsin \theta = 250sin45 = 176.78 \ N$

Applied force in x-direction, $F_x = Fcos \theta = 250cos45 = 176.78 \ N$

The normal force is calculated as;

N + Fy -W = 0

N = W - Fy

N = (100 x 9.8) - 176.78

N = 980 - 176.78 = 803.22 N

The frictional force is given by;

Fk = μN

Fk = 0.12 x 803.22

Fk = 96.386 N

(a) The net force is given by;

$F_{net} = F_x - F_k\\\\F_{net} = 176.78-96.386\\\\F_{net} = 80.394 \ N$

Apply Newton's second law of motion;

F = ma

$a = \frac{F_{net}}{m}\\\\ a = \frac{80.394}{100}\\\\ a = 0.804 \ m/s^2$

(b) the velocity of the crate after 5.0 s

$F = ma= \frac{m(v-u)}{t} \\\\Ft =m(v-u)\\\\v-u = \frac{Ft}{m}\\\\ v = \frac{Ft}{m} + u\\\\v = \frac{F_{net}*t}{m} + u\\\\v = \frac{80.394*5}{100} + 1\\\\v = 5.02 \ m/s$

7 0

2 years ago

Thermodynamics

Marizza181 [45]

Answer:

A heat engine is a device that converts internal energy into work. Internal energy is increased by the addition of heat. The efficiency of a heat engine is a measurement of how efficiently it works. Efficiency compares the amount of useful energy extracted from a process to the total energy input. The heat engine will be more efficient if the percentage is higher.

Explanation:

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2 years ago

Which of these words describes humans

MA_775_DIABLO [31]

Human are eurkaryotic. Eukaryotes are organisms that have cells with a nucleus. Prokayotes are cells without a nucleus. Protists are eukaryotic but they are usually single cellular. Also, human are not fungus. Fungus cannot move and have to get food from its surrounding area.

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3 years ago

How is velocity different from speed? Based on distance and/or direction

Mnenie [13.5K]

Answer:

Speed is solved with time and distance but has no direction

Average velocity is solved with Δx/Δt and has a direction

6 0

2 years ago

Four different resistors have various amounts of electric current flowing through them. Given the values of current I and resist

Artemon [7]

You did not provide the options. However, the options are

I = 6.0, R= 4.0 ohms

I = 9.0, R= 2.0ohms

I = 3.0, R= 2.0ohms

I = 8.0, R= 8.0 ohms

Answer:

The order of the resistors from the highest to the lowest is:

I = 8.0, R= 8.0 ohms

I = 6.0, R= 4.0 ohms

I = 9.0, R= 2.0ohms

I = 3.0, R= 2.0 ohms

Explanation:

ohm's law states that voltage across a conductor is directly proportional to the current flowing through it. V = IR

Based on this formula, the voltages in each of the resistors are calculated below from the highest to the lowest

For I = 8.0, R= 8.0 ohms

V = 8 * 8 =64 volts

For I = 6.0, R= 4.0 ohms

V = 6 * 4 =24 volts

For I = 9.0, R= 2.0 ohms

V = 9 * 2 =18 volts

For I = 3.0, R= 2.0 ohms

V = 3 * 2 =6 volts

3 0

2 years ago