Descirbe an activity to know the centre of gravity of a India map.

Write an activity to know the reaction of bases with metals.

A uniform rectangular block of mass 50 kg is hung horizontally with the help of three wires A, B and C each of length and area of 2 m and 10 mm^2 respectively as shown in the figure. The central wire is passing through the centre of gravity and is made of a material of Young's modulus 7.5 xx 10^10 Nm^(-2) and the other two wires A and C symmetrically placed on either side of the wire B are of Young's modulus 10^11 Nm^(-2) . The tension in the wires A and B will be in the ratio of

A non-uniform bar of weight W is suspended at rest by two strings of negligible weight as shown in Fig.7.39. The angles made by the strings with the vertical are 36.9^(@) and 53.1° respectively. The bar is 2 m long. Calculate the distance d of the centre of gravity of the bar from its left end.

A man of mass 100 kg gets into a car. If the centre of gravity of the car system is depressed by 5mm. Spring constant of the system is ---