Answer:
254 °C
Explanation:
The average kinetic energy of gas molecules K = 3RT/2N where R = gas constant = 8.314 J/mol-K, N = avogadro's constant = 6.022 × 10²³ atoms/mol
T = temperature in Kelvin.
Let K be its average kinetic energy at t = -19°C = 273 + (-19) = 273 - 19 = 254 K = T. K = 3RT/2N = 3 × 8.314 J/mol-K × 254 K/(2 × 6.022 × 10²³ atoms/mol) = 5.26 × 10⁻²¹ J
When its average kinetic energy doubles, it becomes K₁ = 2K = 2 × 5.26 × 10⁻²¹ = 10.52 × 10⁻²¹ J at temperature T₂. So,
K₁ = 3RT₁/2N
T₁ = 2NK₁/3R
T₁ = 2 × 6.022 × 10²³ atoms/mol × 10.52 × 10⁻²¹ J/3 × 8.314 J/mol-K = 508 K
The temperature difference is thus ΔT = T₁ - T = 508 K - 254 K = 254 K.
Since temperature change in kelvin scale equals temperature change in Celsius scale ΔT = 254 °C
So, we need to change the temperature of the air by 254 °C to double its average kinetic energy.
A: geologist
b: physical science
c: space science
d: ecologist
Answer:
3. velocity is zero.
Explanation:
The velocity of a simple harmonic motion is given by
Here, <em>ω</em> is the angular velocity, <em>A</em> is the amplitude (or maximum displacement from the equilibrium point) and <em>x</em> is the displacement at any time.
At maximum displacement, <em>x </em>=<em> A</em>.<em> </em>Then
Therefore, at maximum displacement, velocity is 0.
Practically, this can be observed in a simple pendulum. As it approaches the maximum displacement, its velocity reduces. It becomes zero at this point and then reverses as the pendulum changes course. Then the velocity begins to increase. It becomes maximum at the equilibrium point but once past that, the velocity begins to reduce as it approaches the other amplitude.
For acceleration,
It follows that at maximum displacement, the acceleration is a maximum. The negative sign indicates that it is in an opposite direction to the displacement. Both kinetic energy () and linear momentum () are proportional to velocity; they are therefore both zero at the maximum displacement.
Answer: B, increase the rate at which he turns the crank
Explanation: i got it right