Answer:
a) The potential energy in the system is greatest at X.
Explanation:
Let be X the point where a ball rests at the top of a hill. By applying the Principle of Energy Conservation, the total energy in the physical system remains constant and gravitational potential energy at the top of the hill is equal to the sum of kinetic energy, a lower gravitational energy and dissipated work due to nonconservative forces (friction, dragging).

Conclusions are showed as follows:
a) The potential energy in the system is greatest at X.
b) The kinetic energy is the lowest at X and Z.
c) Total energy remains constant as the ball moves from X to Y.
Hence, the correct answer is A.
Answer:
w = 1.976 rpm
Explanation:
For simulate the gravity we will use the centripetal aceleration
, so:

where w is the angular aceleration and r the radius.
We know by the question that:
r = 60.5m
= 2.6m/s2
So, Replacing the data, and solving for w, we get:

W = 0.207 rad/s
Finally we change the angular velocity from rad/s to rpm as:
W = 0.207 rad/s = 0.207*60/(2
)= 1.976 rpm
Both options 5 and 6
Explanation:
Let us consider option 5,
In option 5 body is moving up with initial velocity lower than that of final velocity which gets accelerated. Therefore the acceleration is positive in this case.
Let us consider option 6,
In option 6 body is moving down with initial velocity lower than that of final velocity which gets accelerated. Therefore the acceleration is positive in this case.
Answer:
Electric current is electric charge in motion. It can take the form of a sudden discharge of static electricity, such as a lightning bolt or a spark between your finger and a ground light switch plate. ... Most electric charge is carried by the electrons and protons within an atom.
Explanation:
because it is