Why is it important to create pictorial and physical models before trying to solve an equation, solving a physics problem

The pictorial and physical model help in many ways when we solve physics problems.

A pictorial representation of data refers to the presentation of data in different symbols or pictures of different objects.It gives the idea of deeper understanding of the problem. It makes the data clear and useful,and helps in comparing it with different parameters.

A physics problem is not always full with digits and equations.Sometimes a problem require higher understanding .Physical model plays a crucial role in this situation.It eradicates all the ambiguity and provides the idea to solve the problems pragmatically.

b) phosphorus pentoxide

see the picture for the vector

the magnitude of the vector by pythagorean theorem

r = √( (-10)^2 + (3)^2 ) = √109

magnitude = √109 units

the direction angle between vector and x-axis is

tan^(-1)(3/10) = 16.699

so the direction is approximately 16.7 degrees north of west