Thermal Expansion. best describes the increase in a materials volume
Answer:
Δu=1300kJ/kg
Explanation:
Energy at the initial state
Is saturated vapor at initial pressure we have
Process 2-3 is a constant volume process
The overall in internal energy
Δu=u₁-u₃
We replace the values in equation
Δu=u₁-u₃
Δu=1300kJ/kg
The correct answer is:
<span>C) The actual frequency of the siren does not change despite appearances.
In fact, Bob will observe an increase in the apparent frequency as the emergency vehicle approaches him, while Jill will observe a decrease in the apparent frequency as the emergency vehicle moves away from him, because of the Doppler effect (the relative velocity between the observer and the source of the sound is changing), but this effect involves the apparent frequency, while the real frequency of the siren will remain the same.</span>
Explanation:
a. KE at bottom = PE at top
½ mv² = mgh
v = √(2gh)
v = √(2 × 9.8 m/s² × 20.0 m)
v = 19.8 m/s
b. Work by friction = PE at top
mgμ d = mgh
d = h / μ
d = 20.0 m / 0.210
d = 95.2 m