Circle the right answers.

I. Which of the following is a proper unit of weight:

    A.    Kgm²s^-1
    B.    Kgm²s^-2
    C.    Kgms^-1
    D.    Kgms^-2
    E.    ms^-2

Ans. D

II.

What is the normal force acting on the block by the floor?

    A.    1153 N
    B.    980 N
    C.    880 N
    D.    1080 N
    E.    807 N

Ans. C

III.

A football is kicked with an initial speed of 25 m/s at a certain non-zero angle with the horizontal. Which of the following statements is not correct?

    A.    The horizontal component of velocity of the football is always 25cos (in m/s).
    B.    The football will have the longest range if it is kicked at = 45^o.
    C.    The football will have the same range if it is kicked at = 20^o or = 70^o.
    D.    The football is always accelerating downward with an acceleration of 9.8 m/s².
    E.    The football rests instantaneously when it reaches the highest point.

Ans. E