Short Answer TypeDefine Newton, the S.I. unit of force. State its relationship with the C.G.S. unit of force.
State the amount of work done by an object when it moves in a circular path for one complete rotation. Give a reason to justify your answer.
The amount of work done will be equal to zero. This is because, work is said to be done only when there is a displacement produced. In case of a body moving in a circular path, the body comes to its original place, therefore, there is no displacement and hence work is zero.
Calculate the height through which a body of mass 0.5 kg should be lifted if the energy spent for doing so is 1.0 Joule.
Show that for the free fall of a body, the sum of the mechanical energy at any point in its path is constant.
A uniform metre scale is kept in equilibrium when supported to the 60 cm mark and a mass M is suspended from the 90 cm mark as shown in the figure. State with reasons, whether the weight of the scale is greater than, less than or equal to the weight of mass M. 
Name the type of single pulley that can act as a force multiplier. Draw a labelled diagram of the above named pulley.
A pulley system has a velocity ratio of 4 and an efficiency of 90%. Clculate:
i) the mechanical advantage of the system.
ii) the effort required to raise a load of 300 N by the system.Give one use each of the electromagnetic radiations given below:
i) Microwaves
ii) Ultraviolet radiations
iii) Infrared radiation.
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