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
True, the measurement shown is a derived unit.
Answer:
Its length is measured to be 0.5 m
Explanation:
From theory of relativity (mass variation), we know that:
m = mo/√(1-v²/c²)
Where, m = relative mass
and, mo = rest mass
The momentum of stick while moving, will be:
P = mv
but, it is given in the form of rest mass as:
P = 2(mo)v
thus, by comparison;
2(mo)v = mv
using value of m from theory of relativity;
2(mo)v = (mo)v/√(1-v²/c²)
√(1-v²/c²) = 1/2 ______ eqn(1)
Now, for relativistic length (L), we have the formula from same theory of relativity;
L = (Lo)√(1-v²/c²)
The rest length (Lo) of meter stick is 1 m, and the remaining term on right side √(1-v²/c²), known as Lorentz Factor, can be given by eqn (1), as equal to 1/2.
Thus,
L = (1 m)(1/2)
<u>L = 0.5 m</u>