State one way in which the friction between wheel and its axle can be reduced.

Describe the various methods by which friction between two surfaces can be reduced.

Figure-2.85 shows a block B of mass m, cart C of mass M, and the coefficient of static between the block and the cart is mu . Neglect frictional between wheels and axles and the rotational effects of the wheels. Determine the minimum value of F which must be applied on B such that it will not slide. [(mg)/(mu)(1+(m)/(M))]

State two ways by which rusting can be prevented ?

State three ways in which the strength of an electromagnet can be increased.

State two ways by which rusting can be prevented.