141. If a man standing at the equators on earth feels weightlessness, then the length of one day will be (approximately): (1) 12 h (2) 6h (3) 2.4 h (4) 1.4 h 142. One end of uniform wire of length L and weight W is attached rigidly to a point in the roof and a weight W, is suspended from its lower end. If S is the area of cross section of the wire, the stress in the wire at a height (L/4) from its lower end is W W+ 1 4 (1) S W, + 1 +3W W + W (4) 4 S 4 43. Four wires of same material are stretched by the same load. The dimensions of wires are given below. Which of them will elongate the most? (1) Length 1.0 m, diameter 1 mm (2) Length 2.0 m, diameter 2 mm (3) Length 1.0 m, diameter 2 mm (4) Length 4.0 m, diameter 1 mm 144. If work required to blow a soap bubble of radius R is W, then the additional work required to blow its radius upto 3 R will be (1) 27 W (2) 9 W (3) 8 W (4) 3 W 145. If a capillary of radius r is dipped in water, the height of water that rises in it is h and mass of water in capillary is M. If the radius of the capillary is doubled, the mass of water that rises in the capillary will be M (1) 2 (3) 2M (2) M (4) 4M