1.	Circle the right answers.

	(I).	The three basic SI units used in mechanics are:
		A.	cm, g, and s
		B.	m, kg, and s
		C.	m, g, and s
		D.	mm, cm, and m
		E.	None of above

	(II).	A stone is thrown vertically upward and then it falls back to the hand at the original position.  Which of the following statement is wrong:
		A.	The velocity of the stone is zero when it reaches the highest position.
		B.	Acceleration changes direction when the stone turns around at the highest point.
		C.	Average velocity of the stone is zero.
		D.	Average speed of the stone is not zero, but a positive number.
		E.	How high the stone will travel depends on the initial speed it is thrown upward.

	(III).	Two bricks of masses m and 2m are thrown vertically upward at the same height, at the same time, and with the same initial speed.  Neglect air resistance.  Which of the following statement is wrong?
		A.	The lighter brick will reach a higher point than the heavier brick.
		B.	Both bricks will fall back to ground at the same time.
		C.	Both bricks will move with the same velocity and acceleration all the time.
		D.	If the experiment is done on the Moon's surface (with the same initial speed), it will take longer for the bricks to reach the ground.
		E.	If the experiment is done on the Moon's surface (with the same initial speed), both bricks will reach a higher height.

	(IV).	Which of the following cannot be units (not necessary SI) for acceleration?
		A.	km h-2
		B.	m s-2
		C.	(m-0.5s)-2
		D.	cm s-1 h-1
		E.	mm h s-1

	(V).	Which of the following statement is wrong about the acceleration due to gravity:
		A.	g ~ 9.80 m/s2 on Earth's surface.
		B.	g on Moon's surface is smaller than the g value on Earth's surface.
		C.	g will become smaller at higher altitude.
		D.	Acceleration due to gravity is always negative for upward moving object, and it is always positive for falling object. 
		E.	In outer space, far from any astronomical objects like stars and planets, g ~ 0 m/s2.