Question 1
a) A suction cup is used to support a plate of weight W as shown in Figure. For the
conditions shown, determine W. (water = 62.4 Ib/ft3, water= 1.94 slugs/ft3). (10 Marks)
b) For the gate shown in Figure, calculate the height H that will result in the gate
opening automatically if l = 1 m (neglect the weight of the gate). The depth normal to
the diagram is w = 1 m. (10 Marks)
Question 2 (20 Marks)
In this system, d = 15 cm., D = 30 cm, z1= 2 m and z2 = 4 m. The discharge of water (
 = 996 kg/m3) in the system is 16 m3/min and the friction losses are negligible.
a ) Is the machine a pump or a turbine?
b) What are pressures at points A and B?
Question 3 (20 Marks)
A two-dimensional reducing bend has a linear velocity profile at section 1. The flow is
uniform at sections 2 and 3. The depth normal to the diagram is w = 1 m. The fluid is
water and the flow is steady.
a- Find the magnitude and direction of the uniform velocity at section 3.
b- Evaluate the net momentum flux in x-direction.
Bonus (5 Marks, based on the final answer)
Consider the act of spreading soft butter on bread with a knife. In essence, we have a
stationary surface (the bread), a moving surface (the knife), and a Newtonian fluid
occupying the space in between. The part of the knife in contact with the butter has
dimension of 9 cm x 1.6 cm. The knife is moved across the bread at a rate of 5 cm/s. The
average thickness of the butter during the process is about 2 mm (a rough
approximation).
a. Calculate the shear stress exerted on the butter if the force required
to move the knife is 0.07 N.
c. Calculate the dynamic viscosity of the butter.
Midterm Exam ENGR 361
State any assumptions, missed information, properties ….etc.