Answer:
9 cm.
Explanation:
The energy used for stretch the spring from
to
will be ,
The energy used for stretch the spring from
to
will be ,
using the energy of spring formula ,we find that


Dividing both the equation will get,

Therefore, the natural length of the spring is, 9 cm.
Answer:

Explanation:
<u>Average Density
</u>
The density of an object of mass m and volume V is

If we know the density and the volume occupied by the object, the mass can be computed as

The tank can hold 20 L of gasoline when full. Converting to cubic meters

That's the volume of the gasoline it contains. Knowing the density of the gasoline, we get the mass of gasoline.

To know the total mass of both, we add the 2.5 kg of the tank

The volume of the tank is computed solving for V


The total volume is

The average density is


The bowling ball is at rest, so it only has gravitational potential energy.
Ug = mgy
Ug = (2)(9.8)(40) = 784 J
Need any more help?