Section 7 & 9

Quiz ( 1)-Ch(1)

Key Phys 101 ( Term 032)-( F. Enaya)

 


** Show your steps clearly for full credit.!! **

 

Q1. The acceleration { a } of an object moving along x-axis is given by: a = x n v p m q

 

where { x } is the distance, { v } is the speed and { m } is the mass of the object. Find the values of {n}, {p} and {q} so that the above equation is dimensionally correct.

 

 

Using basic Units ( L, T and M) : a = x n v p m qÞ(L/T 2) = Ln. (L/T) p.M q

Þ L1. T-2= L ( n+ p). T p .M q Þ

 

n + p = 1 , and - p = -2 Þ ( p = 2) & ( n = - 1), where there is no (M) in the left side Þ (q = 0)

 

 

 

 

 

 

 

Q2. An astronomical unit (AU), is the average distance of the earth from the sun, approximately 1.49108 km.

The speed of the light is about 3108 m/s. Express the speed of light in terms of astronomical units per hour.