question_answer

Fill in the blanks. (a) Friction opposes the _____ between the surfaces in contact with each other. (b) Friction depends on the ______ of surfaces. (c) Friction produces.______. (d) Sprinkling of powder on the carrom board _____ friction. (e) Sliding friction is _____ than the static friction. (f) The force of friction always ____ the motion of an object. (g) Friction _____when you press the two surfaces hard together. (h) The smoother a surface is, the____ will be the friction. (i) Rolling friction is____ than sliding friction. (j) The soles of our shoes wear out-in a few months due to____ (k)  ____is a self-adjusting force. (l) The force of friction which does not allow one body to slide upon another is called____ (m) Frictional force in a ceiling fan is reduced by using_____ (n) Aeroplanes are streamlined to reduce____ friction. (o) With increase of temperature, the frictional force acting between two surfaces ____ (p) We can not walk on ice or on a very smooth surfaces because friction between our shoes and these   surfaces is ____ (q) The bodies of aeroplanes, missiles, rockets, cars are streamlined to reduce friction with air, called (r) The frictional force that fluids exert on object is called_____ (s) To reduce fluid friction, the shape of object should have a____ (t) Friction can be ____or ____by adopting proper methods. (u) Lubricants are used to ____friction. (v) The friction offered by wheels is called (w) Ball bearings converts the sliding friction to (x) Friction prevents movement until the force applied is____ than the force of friction. (y) Friction is a ____ force.

Answer:

(a) motion (b) nature (c) heat (d) reduces (e) less (f) Opposes (g) Increases (h) Lesser (i) Less (j) Friction (k) Force of friction (l) Sliding friction (m) Ball bearing (n) Fluid or air (o) Decreases (p) Very small (q) Air resistance (r) Drag (s) Streamline (t) Increased, decreased (u) Reduce (v) Sliding friction (w) Rolling friction (x) Greater (y) Contact