Mechanical Engineering Answers

One of the tanks at the Cape Town aquarium is 4m high and has reinforced glass panels along two of the sides. The water in the tank has a density of 1028 kg/m^3. Determine the magnitude of the force on the glass per running meter analytically, as well as the height above the base where this force acts when the tank is 80% full. Now confirm your answer using the pressure distribution diagram method.

It is decided to build a dam in the Breed River. It is suggested that the dam wall has a half parabolic cross-section. It is estimated that the dam will have a depth of 10 m and the civil engineers suggest that the half parabolic width should be at least 3 m. Determine the total force on this wall a'd the direction in which it will act.

HINT: The area enclosed by a parabola is equal to 2/3 the area of the rectangle with the same height and width.

Beer is fermenting in a steel tank that is 5m high. This tank has an access hatch on the side 15 cm above the bottom, for maintenance purposes. The hatch is elliptical with a width of 65cm and a hight of 35 cm. Two bolts of 10mm diameter are used to hold the hatch in place. Determine the stress in each bolt when the level of the beer is 4m above the top of the hatch. Assume the beer to have a density of 650kg/m^3 and the bolts to be horizontally on either side of the centre of pressure. At what depth is the centre of pressure?

The request for this project is to design the diameter of the output shaft of a single reduction with a 20 pressure angle involute spur gear set. The gearbox consists of two shafts, four bearings, two spur gears and gearbox steel casing. The gearbox is powered by a 3kw power, 50Hz AC electric motor with a speed of 1440rpm.The main goal of the gearbox is to reduce the speed to 575 rpm

From the following data, draw the profile of a cam in which the follower moves 

with simple harmonic motion during ascent while it moves with uniformly 

accelerated motion during descent : Least radius of cam = 50 mm ; Angle of 

ascent = 48° ; Angle of dwell between ascent and descent = 42° ; Angle of descent 

= 60° ; Lift of follower = 40 mm ; Diameter of roller = 30 mm ; Distance between 

the line of action of follower and the axis of cam = 20 mm. If the cam rotates at 

360 r.p.m. anticlockwise, find the maximum velocity and acceleration of the 

follower during descent

In a jib crane, the jib and tie rod are 6 m and 5 m long respectively. The height of the crane post is 3 m. When a weight (W) 317 N is suspended from the crane and the tie rod remains horizontal.

Determine the tension in Tie rod (only magnitude, in N)?

A bar LM of weight (W) 80 N is hinged at L and is pulled by a cable attached at M by a force P, as shown in figure below.

Find the magnitude of force P (unit in N)?

G(s)= s+2/ s2 −s−1

a) Draw the block diagram of the system. Make sure you show the reference input 𝑅(𝑠), the output

𝐶(𝑠) and the unity feedback.

 A flat belt, 8 mm thick and 100 mm wide transmits power between two pulleys, running at 1600 m/min. The mass of the belt is 0.9 kg/m length. The angle of lap in the smaller pulley is 165° and the coefficient of friction between the belt and pulley is 0.3. If the maximum permissible stress in the belt is 2 MN/m2, find : 1. maximum power transmitted ; and 2. initial tension in the belt

The power transmitted between two shafts 3.5 metres apart by a cross belt drive round the two pulleys 600 mm and 300 mm in diameters, is 6 kW. The speed of the larger pulley (driver) is 220 r.p.m. The permissible load on the belt is 25 N/mm width of the belt which is 5 mm thick. The coefficient of friction between the smaller pulley surface and the belt is 0.35. Determine : 1. necessary length of the belt ; 2. width of the belt, and 3. necessary initial tension in the belt.