Help please What is one purpose of studying economics?

- To understand the reasons why people purchase certain goods.
-To find reasons why some resources become scarce.
-To determine the principles that explain why consumers buy services.
-To examine principles that influence the production of goods and services.

Line joining liquid phase with liquid and solid phase mixture is known as: a) liquidus b) solidus c) tie line d) none of the mentioned

If a particle moves along a path such that r : (3 sin t) m and ? : 2t rad, where t is in seconds. what is the particle's acceleration in m/s in 4 seconds? a)- 16.43 b)- 16.29 c)- 15.21 d)- 13.79

Ifa component is made of two or more materials with different modulus of elasticity (e), it is called a composite member and we calculate the factor·n". mention the formula for calculating n". also, ifn> 1, explain what will happen to the 1. transformed. gi) ifn 1, what will happen to the material when transformed material when