SOL1-2011

# SOL1-2011 - ECH 152A Fall 2010 Roland Faller Solution for...

This preview shows pages 1–2. Sign up to view the full content.

ECH 152A, Fall 2010, Roland Faller Solution for Homework 1, October 1, 2011 Problem 1 UNITS Electric current is the fundamental SI dimension with unit Ampere . For the following quantities combine fundamental SI units to obtain derived SI units Electric power, electric charge, resistance, and voltage. Solution Power P = U × I [ P ] = W = VA = J C C s = J s = kgm 2 s 3 Charge Q = I s [ Q ] = C = As Resistance R = U I [ R ] = Ω = V A = J CA = kgm 2 A 2 s 3 Voltage U = J Q [ U ] = V = J C = kgm 2 As 3 Problem 2 A mercury manometer at 25 C gives a reading of 71.38 cm at a point where the local acceleration of gravity is 9.82 ms - 2 . The atmospheric pressure is 100.78 kPa. What is the absolute pressure being measured? ( ρ Hg (25C) = 13 . 534 gcm - 3 . How does it change with the local acceleration of gravity? Solution The pressure measured in the manometer corresponds to p = ρgh = 13 . 534gcm - 3 9 . 82ms - 2 71 . 38cm = 13 . 534 × 9 . 82 × 71 . 38 × 10 3 kgm - 3 ms - 2

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 2

SOL1-2011 - ECH 152A Fall 2010 Roland Faller Solution for...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online