A \(20\) N metal block is suspended by a spring balance. A beaker containing some water is placed on a weighing machine which reads \(40\) N. The spring balance is now lowered so that the block gets immersed in the water. The spring balance now reads \(16\) N. The reading of the weighing machine will be:
1. \(36\) N
2. \(60\) N
3. \(44\) N
4. \(56\) N

A piece of wood is floating in water kept in a bottle. The bottle is connected to an air pump. Neglect the compressibility of water. When more air is pushed into the bottle from the pump, the piece of wood will float with

1. larger part in the water

2. lesser part in the water

3. same part in the water

4. it will sink

A metal cube is placed in an empty vessel. When water is filled in the vessel so that the cube is completely immersed in the water, the force on the bottom of the vessel in contact with the cube:
1. will increase
2. will decrease
3. will remain the same
4. will become zero

A wooden object floats in water kept in a beaker. The object is near a side of the beaker (figure). Let \(P_1,\) \(P_2,\) \(P_3\) be the pressures at the three points A, B and C of the bottom as shown in the figure.

Then:
1. \(P_1=P_2=P_3\)
2. \(P_1<P_2<P_3\)
3. \(P_1=P_2\neq P_3\)
4. \(P_2=P_3\neq P_1\)

A closed cubical box is completely filled with water is accelerated horizontally towards right with an acceleration a. The resultant normal force by the water on the top of the box:

1. passes through the centre of the top.

2. passes through a point to the right of the centre.

3. passes through a point to the left of the centre.

4. becomes zero.

Consider the situation of the previous problem. Let the water push the left wall by a force F₁ and the right wall by a force F₂

1. F₁ = F₂

2. F₁ > F₂

3. F₁ < F₂

4. The information is insufficient to know the relation between F₁ and F₂

Previous problem: A closed cubical box is completely filled with water is accelerated horizontally towards right with an acceleration a.

Water enters through end \(A\) with a speed \(v_1\) and leaves through end \(B\) with a speed \(v_2\) of a cylindrical tube AB. The tube is always completely filled with water. In case I the tube is horizontal, in case II it is vertical with the end \(A\) upward and in case III it is vertical with the end \(B\) upward. We have \(v_1=v_2\) for:
1. case I
2. case II
3. case III
4. each one

Bernoulli's theorem is based on the conservation of:

Water is flowing through a long horizontal tube. Let \(P_A\) and \(P_B\) be the pressures at two points \(A\) and \(B\) of the tube.

Water and mercury are filled in two cylindrical vessels up to the same height. Both vessels have a hole in the wall near the bottom. The velocity of water and mercury coming out of the holes are v₁ and v₂ respectively.

1. v₁ = v₂

2. v₁ = 13.6 v₂

3. v₁ = v₂/13.6

4. v₁ = \(\sqrt{13.6}\)v₂