Answer:
121.0 W
Explanation:
We use the equation for rate of heat transfer during radiation.
Q/t = σεA(T₂⁴ - T₁⁴)
Since temperature of surroundings = T₁ = -20.0°C = 273 +(-20) = 253 K, and temperature of skier's clothes = T₂ = 5.50°C = 273 + 5.50 = 278.5 K.
Surface area of skier , A = 1.60 m², emissivity of skier's clothes, ε = 0.70 and σ = 5.67 × 10⁻⁸ W/m²K⁴
.
Therefore, the rate of heat transfer by radiation Q/t is
Q/t = σεA(T₂⁴ - T₁⁴) = (5.67 × 10⁻⁸ W/m²K⁴
) × 0.70 × 1.60 m² × (278.5⁴ - 253⁴) = 6.3054 × (1918750544.0625) × 10⁻⁸ W = 1.2098 × 10² W = 120.98 W ≅ 121.0 W
Answer:
Explanation:
3. The word circuit means "go around", therefore a circuit is a pathway or closed path around which electricity (or water) flows.
4. Electrons flowing through a wire can be compared to water flowing through a hose. Once the flow of electrons or water is going, work, is performed.
5. You would get shocked in a bumper car by touching the floor and the ceiling at the same time. This means you are completing the circuit allowing electricity to flow.
6. Electricity from a wall outlet has enough energy to stop your
heart.
7. Electricity is the flow of electrons, because electrons move or jump from atom to atom.
8. Materials that allow electrons to move easily from atom to atom are called conductors.
9. Materials that do not allow electrons to flow easily are called insulators.
10. Semi- conductors are materials that are somewhere in between
.
11. Voltage is the force or pressure of electricity and is compared to the amount of water pressure in a hose.
12. Current (amps
) is the amount of electricity and is compared to the amount of water in a hose
.
13. Watts (power) is the term for work performed by electricity.
<h2>Answer: The more precisely you know the position of a particle, the less well you can know the momentum of the particle
</h2>
The Heisenberg uncertainty principle was enunciated in 1927. It postulates that the fact that each particle has a wave associated with it, imposes restrictions on the ability to determine <u>its position and speed at the same time. </u>
In other words:
<em>It is impossible to measure simultaneously (according to quantum physics), and with absolute precision, the value of the position and the momentum (linear momentum) of a particle.</em>
<h2>So, the greater certainty is seeked in determining the position of a particle, the less is known its linear momentum and, therefore, its mass and velocity. </h2><h2 />
In fact, even with the most precise devices, the uncertainty in the measurement continues to exist. Thus, in general, the greater the precision in the measurement of one of these magnitudes, the greater the uncertainty in the measure of the other complementary variable.
Therefore the correct option is C.
