Fill in the blanks with missing words:
The maximum value of the force of friction is called ________ friction.
Question 1 (a) Fill the missing word in the blank spaces in the following statements: (a) Wind is ––––– air.
The force of friction is a self adjusting force only _________ motion ensures.
The force of friction always acts in a direction ________ to that in which motion is desired.
The heat produced by friction can be used for __________ a matchstick.
A force may sometimes only _________ to produce motion.