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 ^q Þ (L/T ²) = Lⁿ . (L/T) ^p . M ^q

Þ L^{1 .} 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 1.49´10⁸ km.

The speed of the light is about 3´10⁸ m/s. Express the speed of light in terms of astronomical units per hour.