What does an electromagnet have that a bar magnet does not ?

Answer: Option (A)

Explanation: Silica rich magma are those in which the magma has more than 65 % of silica content. The higher the silica content, the higher is its viscosity i.e viscosity of a magma is directly proportional to the silica content of magma.

This highly viscous magma inside the volcanoes moves sluggishly and mostly gets concentrated in the vents and seals them. With time, when the pressure exerted by the magma is too high, it creates violent eruptions through the vents.

Thus, the correct answer is option (A).

Answer:

A. Highly viscous and associated with violent eruptions

Explanation:

Most silica rich magma have high viscosity and huge amount of trapped gases within them. As they continue to upwell and expand, the gases causes violent eruptions near Volcanoes. Most granitic/rhyolitic magma are silica rich.

The magnitude and direction of the elevator's acceleration would be

Given the Parameters :

• Scale, reading, N = 810 N

• Mass, m = 73 kg
• Acceleration due to gravity, g = 9.8 m/s²

The Normalforce can be calculated using the relation :

Substituting the Parameters into the equation :

Scale reading > weight of woman (73 × 9.8)

810 < 715.4 (acceleration will be upward)

Therefore, the acceleration of the elevator would be

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Answer:

b

Explanation:

n = m(g +a)

n= normal force (N)

m=mass (kg)

g=acceleration of gravity

a= acceleration of elevator

rearrange:

a= n/m - g

a= (810 N/73 kg) - 9.8 m/s ^2

a= 1.3 m/s ^2 up

and the acceleration is upwards bc her weight is less than the scale reading

Answer:

large balloon

Explanation:

Thermal energy is the amount of energy contained in a system solely by the effect of its temperature. However, this concept should not be confused with that of internal energy. Internal energy, in turn, is defined as the sum of kinetic energy (translational, rotational and vibrational) with the different forms of potential energy (attractive or repulsive) that can exist between the molecules of a body.

Kinetic energy is associated with the movement of molecules, while potential energy is energy that can be stored in a physical system. In the case of balloons filled with air or liquids, the larger the balloon, the greater the kinetic potential and consequently the thermal energy. For example, a large balloon filled with air will have more thermal energy, because it will have more air molecules that will move through the kinetic energy causing thermal energy.

Answer:

Hello! the efficiency of a thermal engine depends on how much of the initial input is transformed into work, Here 270°c is the input and 210°c is the output.

Then the efficiency is calculated as e = 1 - Tc/Th, where Th is the hot temperature (in this case 270°C) and Tc is the cold temperature (in this case 210°C)

First we need to write the temperatures in kelvin degrees, this can be done by adding 273.15 to the celsius scale:

Th = 270 + 273.15 = 543.15

Tc = 210 +273.15 = 483.15

then the efficiency is e = 1 - 543.15/483.15 = 0.11

if we write this as a percentage, we get an efficiency of 11%, then the fourth answer is the correct one.

Answer:

Given:

Th = 270 °C = 270+273 = 543 K, hot temperature

Tc = 210 °C = 210+273 = 363 K, cold temperature

According to the Carnot theorem, the maximum efficiency achievable by a heat engine between a hot and cold temperature is

η = 1 - Tc/Th

  = 1 - 363/543

  = 0.668 = 11.047 (approx)

Answer:  11.0%  (nearest integer)