Answer: coal
Explanation: Nonrenewable energy resources include coal, natural gas, oil, and nuclear energy. Once these resources are used up, they cannot be replaced, which is a major problem for humanity as we are currently dependent on them to supply most of our energy needs
Answer:
Chemical changes are also known as chemical reactions. The “ingredients” of a reaction are called reactants, and the end results are called products.
Explanation:
Answer:

Explanation:
The force of kinetic friction on the block is defined as:

Where
is the coefficient of kinetic friction between the block and the surface and N is the normal force, which is always perpendicular to the surface that the object contacts. So, according to the free body diagram of the block, we have:

Replacing this in the first equation and solving for
:

Answer:
We conclude that the required momentum is 80 kgm/s.
Explanation:
Given
To determine
The momentum p = ?
Important Tip:
- The momentum of an object is the product of mass and velocity.
We can determine the momentum using the formula

where
now substituting m = 20 and v = 4 using the equation


kg m/s
Therefore, we conclude that the required momentum is 80 kgm/s.
The pitcher's power is given by the formula P= fxv
P=100x 45m/s= 4500 Watts