A vector is an arrow that
describes magnitude and
direction.
1. In the vector diagram of an airplane
going crosswind, what does the
diagonal line represent?
Paul rolls a bowling ball across the table
and then represents its velocity on the
chalkboard with VECTORS.
2. Why are the vectors the same size?
3. If the bowling ball is dropped, how
do the vectors compare?
4. What is the numerical value for g for
the planet earth?
5. What does the formula v=gt
represent? What units?
6. If a ball falls past a window at
50 m/s, how fast is it going
1 second later?
7. If a ball is dropped, what is the
formula for how far it falls?
8. If a ball is dropped from the top of a
cliff, how far will it fall in 1 sec?
2 seconds? In 10 seconds?
Paul draws a vector diagram for a ball
rolling off the edge of the table. Only
the vertical component of motion changes:
the horizontal part stays the same.
9. Which hits the ground first, a bullet
dropped from a height, or a bullet
fired simultaneously from the same
height?
Paul demonstrates the independence of
horizontal and vertical motion with a device
that shoots a ball horizontally.
10.If a baseball pitcher throws a ball
horizontally from a tower 5 meters
tall and the ball lands 25 meters
downrange, at what speed was the
ball thrown?
ANSWERS:
1.The resulting direction and the
velocity of the airplane.
2. Two vectors are the same size
to represent constant velocity.
3. When the bowling ball is
dropped the vectors increase
in size to represent the increase
in velocity as the ball falls.
4. The value of g is approximately
10 m/s/s. (m/s 2)
5. The formula v=gt is…
velocity for a freefalling object
where g is 10 m/s/s and t is time
it takes to fall. The unit for speed
is m/s.
6. 60m/s; it gains 10 m/s each second.
7. D = ½ gt2
8. Distance = ½ gt 2
(5)(1) = 5meters
(5)(4) = 20 meters
(5)(100)= 500 meters
9. A bullet shot and a bullet dropped
will both hit the ground at the
same time.
10. Speed= distance/time
25 m/s