ENG102_SL2

# ENG102_SL2 - DATE October 1 2011 DUE October 7 2011 ENG102...

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

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.

Unformatted text preview: DATE: October 1, 2011 DUE: October 7, 2011 ENG102, Solution to homework set #2. 1. After Sample Problem 2/8 in Text: a. Do the problem, answering questions a-d, but start by converting all units into sensible units, e.g., mi → km, ft → m, etc. This should be done while maintaining the physics of the problem intact. Using the conversions, 1 statute mile = 1.609 km and 1 ft = 30.48 cm, we have the given information horizontal acceleration = 6.096 m/s 2 g = 9.144 m/s 2 speed along trajectory = 19,308 km/h = 10,919 m/s. The resulting answers are thereby a n = 7 . 25 m/s 2 , a t = 8 . 26 m/s 2 ; (a) ρ = 3 , 965 km; (b) ˙ v = 8 . 26 m/ 2 ; (c) ˙ β = 1 . 354 × 10 − 3 s − 1 ; (d) ¯ a = 7 . 25 m/s 2 ¯ e n +8 . 26 m/s 2 ¯ e t . Suppose the rocket is experiencing an air-drag that contributes to the total accelera- tion with- α ¯ v , where α is a non-negative constant. Let us denote the angle of the rocket relative to horizontal with θ (that angle is zero as the problem is stated in the book – a positive angle θ will mean that the nose of the rocket will point up relative to its center of mass; this is not necessarily the trajectory of the rocket). b. For α = 0 calculate, as a function of θ ∈ [0 , π 2 ] the total acceleration ¯ a on the rocket. Display the result in the two coordinate systems ¯ e n , ¯ e t and ¯ e x , ¯ e y . We denote the acceleration of the thrust with a th . The acceleration is then ¯ a = a th cos θ ¯ e x + ( a th sin θ- g ) ¯ e y (1) = [( g- a th sin θ ) cos 15 ◦- a th cos θ sin 15 ◦ )] ¯ e n (2) + [( g- a th sin θ ) sin 15 ◦ + a th cos θ cos 15 ◦ )] ¯ e t (3) = [ g- a th sin( θ + 15 ◦ )] ¯ e n + [ g + a th cos( θ + 15 ◦ )] ¯ e t (4) c. For α = 0 . 04 s − 1 , calculate the steady state (constant) velocity of the rocket as...
View Full Document

{[ snackBarMessage ]}

### Page1 / 5

ENG102_SL2 - DATE October 1 2011 DUE October 7 2011 ENG102...

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

View Full Document
Ask a homework question - tutors are online