Find the gravitational potential energy in a 56kg person standing on a cliff 21m off the ground?

Given the resistivities below, which material is best described as an insulator?

koban [17]

Answer: D) 3.2 × 10^8

Explanation: Insulators are best described as materials which are poor conductors of electricity and hence do not allow passage of electricity through them. Resistivity are hence used to describe property or characteristic of a material which does not allow the flow or passage of electric current.

In summary, materials which high resistivity values are referred to as Insulators. Conversely, those with low resistivity or high conductivity values are called conductors while those with intermediate values are named semiconductors.

In the question given above, the material with a resistivity value of 3.2 × 10^8 - - - has a very high resistivity value (320000000Ω), the other options given have very low resistivity values ; 0.0000000017, etc and are most likely to be conductors due to their excessively low resistivity values.

5 0

3 years ago

During normal beating, a heart creates a maximum 3.95-mV potential across 0.305 m of a person’s chest, creating a 0.75-Hz electr

WINSTONCH [101]

Answer:

E = 0.0130 V/m.

Explanation:

The electric field is related to the potential difference as follows:

$E = \frac{\Delta V}{d}$

<u>Where:</u>

E: is electric field

ΔV: is the potential difference = 3.95 mV

d: is the distance of a person's chest = 0.305 m

Then, the electric field is:

$E = \frac{\Delta V}{d} = \frac{3.95 \cdot 10^{-3} V}{0.305 m} = 0.0130 V/m$

Therefore, the maximum electric field created is 0.0130 V/m.

I hope it helps you!

7 0

3 years ago

The Eiffel tower in Paris is 300 meters tall on a cold day (T = -24 degrees Celsius), what is its height on a hot day when the t

Varvara68 [4.7K]

Answer:

Length of Eiffel tower, when the temperature is 35 degrees = 300.21 m

Explanation:

Thermal expansion is given by the expression

$\Delta L=L\alpha \Delta T \\$

Here length of Eiffel tower, L = 300 m

Coefficient of thermal expansion, α = 0.000012 per degree Celsius

Change in temperature, = 35 - (-24) = 59degrees Celsius

Substituting

$\Delta L=L\alpha \Delta T= 300\times 0.000012\times 59=0.2124m \\$

Length of Eiffel tower, when the temperature is 35 degrees = 300 + 0.2124 = 300.21 m

3 0

3 years ago

Review 1: A plane is located x = 40 miles (horizontally) away from an airport at an altitude of h miles. Radar at the airport de

-Dominant- [34]

Explanation:

Let h is the height of the plane above ground. x is the horizontal distance between the ground and the airport. Let s(t) is the distance between the plane and the airport. So,

$s(t)^2={h^2+x^2}$ ...........(1)