Answer:
(A) 7.9 m/s^{2}
(B) 19 m/s
(C) 91 m
Explanation:
initial velocity (U) = 0 mph = 0 m/s
final velocity (V) = 85 mph = 85 x 0.447 = 38 m/s
initial time (ti) = 0 s
final time (t) = 4.8 s
(A) acceleration =
= = 7.9 m/s^{2}
(B) average velocity =
= = 19 m/s
(C) distance travelled (S) = ut +
= (0 x 4.8) + = 91 m
Answer:
c. 2.6 h
Explanation:
The longest time spent over dinner is the time that you have available minus the minimum possible time spent in the trip.
The time of the trip is found using:
t =
Where distance is d and velocity is v. The time will be minimum at maximum velocity. Replacing with the data we have:
Ttrip = = 8.1818 h
Tdinner = 10.8h - 8.1818 h = 2.6181h
that aproximates 2.6 h.
Answer:
Reactance
Explanation:
In an AC circuit, the capacitive reactance of a capacitor is given by:
where
f is the frequency of the AC current
C is the capacitance of the capacitor
The reactance of the capacitor tells somehow the "resistance" of the capacitor to the passage of current through it. In fact:
- When the frequency of the AC current is zero (this means, we are in regime of DC current), the reactance becomes infinite, and this is true because the capacitor does not let the current pass through it)
- When the frequency of the AC current tends to infinite, the reactance becomes zero, and this is true because in this case the current changes direction so fast that the capacitor has not enough time to "block" the current, so the current almost no feels the presence of the capacitor.