Mechanical Engineering Answers

A horizontal axis wind turbine has a rotor diameter of 76 m and reaches its full load output at the generator terminals of 2 MW at a wind speed of 12 m/s. The overall efficiency of the gearbox and generator is 94 %. Assume the density of air is 1.2 kg/m3 and calculate the power coefficient (Cp) of the aerodynamic rotor [6]

Question 1 [20]

A simple gear train of 30 and 50 teeth for pinion and gear wheel respectively, is used to drive an electric wheelchair at a velocity that is double the maximum velocity of slip. The pinion has an equal addendum as the gear wheel, a module of 3 mm, and a pressure angle of 14.5o. The wheelchair has a maximum velocity of 5 m/s when its pinion rotates at 800 r.p.m. Calculate:

1.1. The

1.2. The

1.3. The

1.4. The

1.5. The

1.6. The

magnitude of the velocity of slip of gears in mesh. (2) angular speed of the gear wheel in rad/s. (4) maximum length of a path of the approach in mm. (2) length of a path of a recess in mm. (7) addendum of the gears in mm. (7) contact ratio. (8)

Question 1 [20]

A simple gear train of 30 and 50 teeth for pinion and gear wheel respectively, is used to drive an electric wheelchair at a velocity that is double the maximum velocity of slip. The pinion has an equal addendum as the gear wheel, a module of 3 mm, and a pressure angle of 14.5o. The wheelchair has a maximum velocity of 5 m/s when its pinion rotates at 800 r.p.m. Calculate:

1.1. The

1.2. The

1.3. The

1.4. The

1.5. The

1.6. The

Question 2

magnitude of the velocity of slip of gears in mesh. (2) angular speed of the gear wheel in rad/s. (4) maximum length of a path of the approach in mm. (2) length of a path of a recess in mm. (7) addendum of the gears in mm. (7) contact ratio. (8)

 In a jib crane, the jib and tie rod are 5 m and 4 m long respectively. The height of crane post is 3 m and tie rod remains horizontal. Determine the forces produced in the jib and tie rod when a load of 2 kN is suspended at the crane head

 In a jib crane, the jib and tie rod are 5 m and 4 m long respectively. The height of crane post is 3 m and tie rod remains horizontal. Determine the forces produced in the jib and tie rod when a load of 2 kN is suspended at the crane head

Task 2 

Using the Health and Safety at Work Act 1974 as the principal source of legislation, describe the roles and responsibilities of the following in an electrical and mechanical environment: 

• Employers. 
• Self-employed (subcontractors). 
• Employees. 
• Health and Safety Executive (HSE) Inspectors. 

You should make reference to appropriate regulations where necessary. 

This task provides evidence for grading criterion P2 

the fan has total head of 190 m and A static pressure of 20 cm wg. If the air density is 1.15 kg/m3, what is the velocity of air flowing.

(4x^3-3y^2)dx + 6xydy=0,f(-1)=0