Answer:
2. at the lowest point
Explanation:
The motion of the pendulum is a continuous conversion between kinetic energy (KE) and gravitational potential energy (GPE). This is because the mechanical energy of the pendulum, which is sum of KE and GPE, is constant:
E = KE + GPE = const.
Therefore, when KE is maximum, GPE is minimum, and viceversa.
So, the point of the motion where the KE is maximum is where the GPE is minimum: and since the GPE is directly proportional to the heigth of the bob:

we see that GPE is minimum when the bob is at the lowest point,so the correct answer is
2. at the lowest point
Answer:
dV/dt = 9 cubic inches per second
Explanation:
Let the height of the cylinder is h
Diameter of cylinder = height of the cylinder = h
Radius of cylinder, r = h/2
dh/dt = 3 inches /s
Volume of cylinder is given by

put r = h/2 so,

Differentiate both sides with respect to t.

Substitute the values, h = 2 inches, dh/dt = 3 inches / s

dV/dt = 9 cubic inches per second
Thus, the volume of cylinder increases by the rate of 9 cubic inches per second.
Answer:
Explanation:
A closed system can exchange energy but not matter, with its surroundings. An isolated system cannot exchange any heat, work, or matter with the surroundings, while an open system can exchange energy and matter.
Hope this helped you!
Answer:
8100W
Explanation:
Let g = 10m/s2
As water is falling from 60m high, its potential energy from 60m high would convert to power. So the rate of change in potential energy is
or 9000W
Since 10% of this is lost to friction, we take the remaining 90 %
P = 9000*90% = 8100 W