1) Explain why (a) handles of doors are fixed maximum away from the hinged end of the door (b)heavy vehicles are provided with steering of large diameter (c) workers use long metallic rods for moving heavy loads. (d) We are not able to turn a wheel by pushing along its radius? (e) It is hard to open a jam bottle using just one finger.
2) Where must an 800N object be hung on a uniform rod of weight 100 N so that a girl at one end supports 1/3rd of the weight as compared to that supported by a woman at the other end?
3) A metre stick is balanced on a knife edge at its centre. When two masses each of mass 15 g are put one on top of the other at the 22.0 cm mark, the stick is found to be balanced at 45.0 cm. What is the mass of the metre stick?
4) a. If ice on the polar caps melts, how it affect the duration of the day b. How acrobats make use the principle of conservation of momentum c. A boy is standing on a turn table rotating at constant angular speed. If he stretches his hands outward how the angular speed of the table affected? d. How you distinguish a raw egg and boiled egg using law of conservation of angular momentum? (both are identical in mass)
5) A student stands at the centre of a turntable with his two arms outstretched. The turntable is set rotating with an angular speed of 80 rev/min. How much is the angular speed of the child if he folds his hands back and thereby reduces his moment of inertia to 2/5 times the initial value ? Assume that the turntable rotates without friction. (b) Show that the child’s new kinetic energy of rotation is more than the initial kinetic energy of rotation. How do you account for this increase in kinetic energy?