A) The kinetic energy of an object is given by:
where m is the mass of the object, and v its speed. For the lion in our problem, m=45 kg and v=14.2 m/s, so its kinetic energy is
b) the increase in gravitational potential energy of the lion is given by:
where g is the gravitational acceleration, and
is the increase in altitude of the lion. In this problem, 
, so the increase in gravitational potential energy is
c) When the fox reaches the top of the tree, its gravitational potential energy is
As it jumps, its kinetic energy is
So the total mechanical energy of the fox as it jumps is
where m is the mass of the object, and v its speed. For the lion in our problem, m=45 kg and v=14.2 m/s, so its kinetic energy is
b) the increase in gravitational potential energy of the lion is given by:
where g is the gravitational acceleration, and
c) When the fox reaches the top of the tree, its gravitational potential energy is
As it jumps, its kinetic energy is
So the total mechanical energy of the fox as it jumps is