Physical, chemical, chemical, physical, I’m pretty sure. Natural things, like you starting to breathe heavier are physical most of the time!!!
Answer:
Here is the solution hope it helps:)
Answer:
The friction force is 250 N
Explanation:
The desk is moving at constant velocity. This means that its acceleration is zero: a = 0. Newton's second law states that the resultant of the forces acting on the desk is equal to the product between mass (m) and acceleration (a):

In this case, we know that the acceleration is zero: a = 0, so also the resultant of the forces must be zero:
(1)
We are only interested in the forces acting along the horizontal direction, since it is the direction of motion. There are two forces acting in this direction:
- the pull, forward, F = 250 N
- the friction force, backward, 
Given (1), we have

So the force of friction must be equal to the pull:

Answer:
a,b,c,e,d
Explanation:
The typical approach by the scientists use to understand the physical world includes the following steps:
Identifying a Problem
Researching the Information
Stating a Hypothesis (Possible Solution)
Testing the Hypothesis
Gather Data
Analysis of the Data
Stating a Conclusion
Publishing the Result
Therefore, according to the question the correct order would be:
a. Observation of physical world.
b. Create hypothesis about observation.
c. Test consequences of hypothesis
e. Adjust results to agree with popular opinion
d. Report outcome
Energy can change forms and be transferred.