Answer:
=118.8 K= 154.2°C
Explanation:
COP_max of carnot heat pump=
where T_H and T_C are temperatures of hot and cold reservoirs
Also COP=
in the question
⇒
heat is added directly to be as efficient as via heat pump
and T_H= 24° C= 297 K
on calculating the above equation we get
=118.8 K
the outdoor temperature for efficient addition of heat to interior of home
=118.8 K= 154.2°C
Answer:
<em>The kinetic energy of a spinning disk will be reduced to a tenth of its initial kinetic energy if its moment of inertia is made five times larger, but its angular speed is made five times smaller.</em>
<em></em>
Explanation:
Let us first consider the initial characteristics of the angular motion of the disk
moment of inertia =
angular speed = ω
For the second case, we consider the characteristics to now be
moment of inertia = (five times larger)
angular speed = ω/5 (five times smaller)
Recall that the kinetic energy of a spinning body is given as
therefore,
for the first case, the K.E. is given as
and for the second case, the K.E. is given as
<em>this is one-tenth the kinetic energy before its spinning characteristics were changed.</em>
<em>This implies that the kinetic energy of the spinning disk will be reduced to a tenth of its initial kinetic energy if its moment of inertia is made five times larger, but its angular speed is made five times smaller.</em>