ME HW2

ME 558/458 Assignment 2 Given 19 March Due 28 Mar NAME ___________________ Page 1/1

Circle Area moment of inertia Ix = π r4 / 4

Ellipse Area moment of inertia Ix = π ab3 / 4

Fig A Ship resistance (KN) versus speed (knots) for a displacement hull, with a mark at a speed–length ratio of 1.34

1. [20 pts] In class we showed the floating ship resistance R in lbs or KN is approximated by the

relationship R = Ro [ v/vo]2 Using this relationship complete Table A

Table A 2 .5m Kayak resistance Estimate the resistance R over the speed range 0< v< 2.5 m/s

Speed v m/s 0.25 0.5 1.0 1.5 2.0 Vo =2.5 m/s

Resistance R, KN Ro =20.0

2. [30 pts] 2.5 m Kayak Data: Waterplane is an Ellipse with a = 1.25 m and b = 0.75 m T=0.3m

Displacement = 0.85 m3 KB = 0.2 m

Req. 2.1 Determine the Ixx for the Kayak at T = 0.3 m Ixx =_________________________ 2.2 Determine the BMt m for the Kayak at T =0.3 m BMt = ________________ 2.3 Determine the KMt m for the kayak at T = 0.3 m KM = __________________ 2.4 With a seated rower the KG = 1.2 m What is the GMt = ____________ Is it stable Yes No

3. {30 pts] For a sailing Kayak, rectangular side hulls l = 0.5 m and beam b = 0.3 m T = 0.1 m are

fitted to the Kayak. Each is 1.7 m from the kayak center to the side hull center.

3.1 Using the parallel axis theorem calculate the Ixx’ for the Kayak with side hulls _____________

3.2 Determine the BMt (assume the Kayak and side hulls has a 0.89 m3) _______________

3.3 Determine the KMt’ for KB = 0.2 m _______________________

4. [20] The Offshore platform has 4 vertical legs supporting the deck. Each leg is 10 m diameter

separated by 40 m. O 40 m O 40 m

O 40 m O

4.1 What is the Ixx of a cylinder ___________________

4.2 What is the Ixx’ of the platform _________________