A hole, and people die if they fall in there.
No they don't. Incident rays parallel to the axis of a concave mirror
reflect from the mirror's surface and converge at its focal point.
........................................................................................
Answer:
20.60 kV
Explanation:
Capacitance of parallel plates without dielectric between them is:

with d the distance between the plates, A the area of the plates and ε₀ the constant
, so :

But the dielectric constant is defined as:

With C the effective capacitance (with the dielectric) and Co the original capacitance (without the dielectric). So, the new capacitance is:

But capacitance is related with voltage by:

with Q the charge and V the voltage, using the new capacitance and solving for V:


I think the correct answer among the choices listed above is option C. Magnetic levitation has been used to innovate transportation. This innovation is commonly known as maglev. It is a new transportation technology where noncontacting vehicles travel above a guideway by magnetic fields.