Answer:
5730 years
Explanation:
The half life of carbon-14 is 5730 years. If 50% of the carbon-14 remains, then exactly 1 half life has passed.
The half-life equation is:
A = A₀ (½)^(t / T)
where A is the remaining amount,
A₀ is the initial amount,
t is time,
and T is the half life.
In this case, A = ½ A₀ and T = 5730.
½ A₀ = A₀ (½)^(t / 5730)
½ = (½)^(t / 5730)
1 = t / 5730
t = 5730
Answer:
The reactance of the capacitor
Explanation:
In an AC circuit containing different elements (capacitors, resistors and inductors), we cannot simply calculate the equivalent resistance of the circuit, so another quantity is used, which is called reactance.
For a capacitor, the reactance is given by:

where:
f is the frequency of the AC current in the circuit
C is the capacitance of the capacitor
The reactance has a similar meaning to that of the resistance for a DC current. In fact, we notice that:
- When f=0 (which means we are in regime of DC current, because the current never changes direction), the reactance is infinite. This is correct: in a DC circuit, the capacitor does not let current pass through it, so it like it has infinite resistance (=infinite reactance)
- When f tends to infinite, the reactance becomes zero: in such situation, the current in the circuit changes direction so quickly that the capacitor has no enough time to "block" the current in the circuit, so it like it has almost zero resistance (zero reactance).
answer:
yes
explanation:
At a separation of the surface of Earth (r=6400km) gravity wants pull the test mass closer and closer. ... So the work done by gravity is NEGATIVE. The gravitational potential energy is negative because us trying to do the opposite of what gravity wants needs positive energy.
Answer:
kinetic
Explanation:
kinetic energy is powered by motion or gravity the steeper the hill is the faster a ball will roll