(Wednesday 19 May 2004, 17:37)
The lean of this tower has been tried to fix several times.
The most recent time I believe was in 2001 when they tried to drill into the
ground and pour cement underneath the sandy surface.

Ex)
A coin is
dropped
in a vacuum tube, find its
displacement
after .30 seconds.

"Step 1
- Read and

underline all the

important
information"

Ex)
A coin is
dropped
in a vacuum tube, find its displacement
after .30 seconds.

"Step
2 - Turn all your

information into letters"

V_{i} = 0(Object is dropped) a = +10. m/s^{2} d = ? t = .30 seconds

"Step
3 - Substitute

and Solve"

d = V_{i}t + 1/2at^{2}

d = 0m/s(.30 sec)+1/2(10. m/s^{2})(.30
s)^{2}

d = 0 + 5(.09)

d = .45 m

Ex)
A coin is dropped
in a vacuum tube, find the
coin's velocity after .30 seconds

Ex)
A coin is
dropped
in a vacuum tube, find the
coin's velocity after .30 seconds

V_{i} = 0 m/s

a = +10. m/s^{2}

(dropped)

V_{f} = ?

t = .30 sec

"Search the
Mechanics

Section on the
equation

sheet to find the

equation that
fits"

V_{f} = V_{i} + at

OR

a = (V_{f} - V_{i})/t

V_{f} = 0 + 10. m/s^{2}(.3 sec)

V_{f} = 3.0
m/s

Ex)
A rocket is fired vertically upward with an initial velocity of 29 m/s.

Find the rocket's maximum altitude.

At Maximum Altitude,

V_{f} = 0 m/s

Ex)
A rocket is
fired vertically upward
with an initial velocity of 29 m/s
.

Find the rocket's
maximum altitude.

Altitude??

V_{i} = +29 m/s

V_{f} = 0 m/s
a = g = -9.8 m/s^{2}

d = ?

V_{f}^{2} = V_{i}^{2}
+ 2ad

(0 m/s)^{2}=(+29 m/s)^{2}+2(-9.8m/s^{2})d

0 = 841 + -19.6d

-841 = -19.6d

43 m

Ex)
An object dropped on planet X falls 64 m in 4 seconds.
Find the acceleration due to gravity on planet X.

Ex) An object
dropped on
planet X
falls 64 m in
4 seconds.
Find the
acceleration due to gravity
on planet X.

V_{i}=
0 m/s
d = 64 m
t = 4 sec
a = ?

d = V_{i}t + 1/2 at^{2}

64 m = 0 m/s(4 sec) + 1/2a(4
sec)^{2}

64 m = 0 + 8a

a = 8 m/s^{2}

AP Question

A ball is thrown upward from a position (y_{0})above
the ground with a velocity of 16 m/s.

Find y_{0 }if it took
3.0 seconds for the ball to hit the ground.

A ball is
thrown upward from a position (y_{0})
above the ground with a velocity of 8 m/s.

Find y_{0 }if it took
3.0 seconds for the ball to hit the ground.

Make this a problem of a ball falling from a height
of 21 m and a velocity of 8 m/s down

a_{y} = +10. m/s^{2} (g)

∆d_{ }= +21 m

V_{i} = +8.0 m/s

(vel. become +8 m/s when ball returns to original
position)

V_{f }= ?

V_{f}^{2} = V_{i}^{2} +
2ad

V_{f}^{2} = 64 + 2(10 m/s^{2})21m

V_{f} = 22 m/s down

OR

V_{f} = 8.0m/s + -10m/s^{2}(3
sec)

V_{f} = -22 m/s

Paul Hewitt Question

When you drop a ball it accelerates downward at 9.8
m/s^{2}. If you instead throw it downward, then its acceleration
immediately after leaving your hand, assuming no air resistance, is

A. 9.8 m/s^{2}.

B. more than 9.8 m/s^{2}.

C. less than 9.8 m/s^{2}.

D. Cannot say, unless the speed of throw is given.

Ex) A basketball player jumped straight up to grab a
rebound. If she was in the air for 0.80 second, how high did she jump?

Treat this as a problem where the player comes down from the peak of her
rebound.

a_{y} = 10. m/s^{2} (g)

d_{ }= ?

V_{i} = 0 m/s

t = .40 sec

∆d = V_{i}t +
1/2at^{2}

∆d =
1/2(10 m/s^{2})(.4 sec)^{2}

∆d = .80 m

Ex) A stone is thrown vertically upward with a speed of 12.0
m/s from the edge of a cliff 70.0 m high.

a) how long does it take to reach the bottom of the cliff?