Answer:
Potential energy only
Explanation:
at the top of its swing the pendulum stops moving , (therefore it has no KINETIC energy) thus all of the energy is stored as potential energy.
Answer:
Speed of the alpha particle is
Explanation:
We have given charge on alpha particle 
Mass of the alpha particle 
Potential difference 
We have to find the speed of the alpha particle
From energy conservation we know that



Mars.
Water exists as small amounts of ice on Mars and as water vapor. It is suspected that Mars used to have flowing water on it, but that there is none left now.
Answer:
Cosmic ray's frame of reference: 99,875 years
Stationary frame of reference: 501,891 years
Explanation:
First of all, we convert the distance from parsec into metres:

The speed of the cosmic ray is

where
is the speed of light. Substituting,

And so, the time taken to complete the journey in the cosmic's ray frame of reference (called proper time) is:

Converting into years,

Instead, the time elapsed in the stationary frame of reference is given by Lorentz transformation:

And substituting v = 0.98c, we find:
