Q 15 Fluid Motion 1 A bucket of

Q 15. Fluid Motion

1. A bucket of water is pushed from left to right with increasing speed across a horizontal surface. Consider the pressure at two points at the same level in the water. 1. It is the same 2. It is higher at the point on the left 3. It is higher at the point on the right 4. At first it is higher at the point on the left but as the bucket speeds up it is lower there 5. At first it is higher at the point on the right but as the bucket speeds up it is lower there

P is higher at the point on the left Slope of water surface is

2. A bucket resting on the floor of an elevator contains an incompressible fluid of density . When the elevator has a downward acceleration of magnitude a the pressure difference between two points in a fluid, separated by a vertical distance h, is given by: . 1. a h 2. g h 3. ( g + a ) h 4. ( g a ) h 5. g a h

3. An object hangs from a spring balance. The balance indicates 30 N in air, 20 N when the object is submerged in water. What does the balance indicate when the object is submerged in liquid with a density that is half of water ? 1. 20 N 2. 25 N 3. 30 N 4. 35 N 5. 40 N

In water In liquid

4. The dimensions of a wooden raft (density = 150 kg/m 3) are 3. 0 m 1. 0 m. What maximum load can it carry in sea water (density =1020 kg/m 3) ? 1. 1350 kg 2. 7800 kg 3. 9200 kg 4. 19, 500 kg 5. 24, 300 kg

At max. load:

5. A block of wood weighs 160 N and has a specific gravity of 0. 60. To sink it in fresh water requires an additional downward force of: 1. 54 N 2. 64 N 3. 96 N 4. 110 N 5. 240 N

Downward

6. Water is streaming downward from a faucet opening with an area of 3. 0 10– 5 m 2. m/s. It leaves the faucet with a speed of 5. 0 The cross sectional area of the stream 0. 50 m below the faucet is: 1. 5 10– 5 m 2 2. 0 10– 5 m 2 3. 2. 5 10– 5 m 2 4. 3. 0 10– 5 m 2 5. 3. 5 10– 5 m 2

eq. of continuity Bernoulli eq.

6. Accelerometer 1. 2. 3. 4. 5.

T a a T