Please need help with ? Number 20

The greatest amount of energy

PSYCHO15rus [73]

The answer is choice-3.

1 newton-meter and 1 joule are the same amount of energy, and 1 watt-hour is 3,600 of those.

"Watt" doesn't belong on the list. It's a unit of power, not energy.

3 0

3 years ago

A steel wire, 3.2 m long, has a diameter of 1.2 mm. The wire stretches 1.6 mm when it bears a load. Young's modulus for steel is

Troyanec [42]

Answer:

The mass, m, of the load = 11.3 Kg

Explanation:

Young's Modulus = Stress / Strain

Stress = Force / Area

Force = mass,m * acceleration due to gravity,g

assuming g = 10ms⁻²

therefore, Force = 10m

m is mass of the load in kilograms

Area of steel wire = π * r^2, where π= 3.14, r = 1.2/2 = 0.6mm or 6.0 * 10^-4m

= 3.14 * (6.0 * 10⁻⁴m)^2 = 1.13*10⁻⁶m²

Stress = 10m / 1.13*10⁻⁶m²

Strain = extension / original length

= (new length - original length)/original length

= (3.2016 - 3.2000)/3.2000

Strain = 0.0005

Using Young's Modulus = Stress / Strain

Note: 1Pa = 1N/m² ; Young's modulus for steel is 2.0 × 10¹¹ Pa or N/m²

2.0*10¹¹ N/m²= Stress / Strain

2.0*10¹¹ = (10m / 1.13*10⁻⁶) / 0.0005

0.0005 * 2.0*10¹¹ = 10m/1.13*10⁻⁶

10m = 1.13*10⁻⁶ * 0.0005*2*10¹¹

10m = 113

m = 11.3 kg

Therefore, the mass, m, of the load = 11.3 Kg

8 0

3 years ago

Why do you think the temperature does not change much during a phase change? If possible, discuss your answer with your classmat

skelet666 [1.2K]

Answer:

Explanation:

The fact is that there exists no temperature change until a phase change is complete. That is to say, during a phase change, the energy that will be supplied is used only to separate the molecules. There is no part of it is used to increase the kinetic energy of the molecules. So its temperature will not rise, not really, since the kinetic energy of the molecules remains the same. Also, it should be noted that the average kinetic energy of the molecules does not change at the moment that melting occurs, thus the temperature of the molecules does not change.

6 0

3 years ago

1. The saw cut that is made at 450-75° angles to the annual rings is called:

ASHA 777 [7]

I think the answer you or looking for is miter saw please tell me if I’m wrong

4 0

3 years ago

A small piece of solid matter traveling through space is called a __________. When it collides with the atmosphere it is called

Oksanka [162]

Answer:

Meteoroid , meteor and meteorite

Explanation:

A meteoroid is a small rocky or metallic body travelling through space. Most are fragments from comets or asteroids

The visible streak of light from space debris is the result of heat as it enters a planet's atmosphere, and the trail of glowing particles that it sheds in its wake is called a meteor, or colloquially a "shooting star" or "falling star". A series of many meteors appearing seconds or minutes apart, and appearing to originate from the same fixed point in the sky, is called a meteor shower. Incoming objects larger than several meters (asteroids or comets) can explode in the air. If a meteoroid, comet or asteroid or a piece thereof withstands ablation from its atmospheric entry and impacts with the ground, then it is called a meteorite.

8 0

3 years ago