# ppt

Mechanics

Nov 14, 2013 (4 years and 6 months ago)

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Predicting Motion

Projectile motion

Circular motion

* Not covering relative motion

A ball is thrown upward at a 45
°

angle. In
the absence of air resistance, the ball
follows a

A.
tangential curve.

B.
sine curve.

C.
parabolic curve.

D.
linear curve.

A ball is thrown upward at a 45
°

angle. In
the absence of air resistance, the ball
follows a

A.
tangential curve.

B.
sine curve.

C.
parabolic curve.

D.
linear curve.

A hunter points his rifle directly at a
coconut that he wishes to shoot off a tree.
It so happens

that the coconut falls from
the tree at the exact instant the hunter
pulls the trigger. Consequently,

A.
the bullet passes above the coconut.

B.
the bullet hits the coconut.

C.
the bullet passes beneath the coconut.

D.
This wasn’t discussed in Chapter 4.

A hunter points his rifle directly at a
coconut that he wishes to shoot off a tree.
It so happens

that the coconut falls from
the tree at the exact instant the hunter
pulls the trigger. Consequently,

A.
the bullet passes above the coconut.

B.
the bullet hits the coconut.

C.
the bullet passes beneath the coconut.

D.
This wasn’t discussed in Chapter 4.

The quantity with the symbol
ω

is called

A.
the circular weight.

B.
the circular velocity.

C.
the angular velocity.

D.
the centripetal acceleration.

The quantity with the symbol
ω

is called

A.
the circular weight.

B.
the circular velocity.

C.
the angular velocity.

D.
the centripetal acceleration.

For uniform circular motion, the
acceleration

A.
points toward the center of the circle.

B.
points away from the circle.

C.
is tangent to the circle.

D.
is zero.

For uniform circular motion, the
acceleration

A.
points toward the center of the circle.

B.
points away from the circle.

C.
is tangent to the circle.

D.
is zero.

Projectile Motion

What is the velocity (vector form) at
t

= 0, 2, and 3 seconds?

Projectile Motion

Projectile Motion

Projectile motion is made up of two independent motions:
uniform motion at constant velocity
in the horizontal
direction and
free
-
fall

motion in the vertical direction. The
kinematic equations that describe these two motions
are:

0 s,
t

0
ˆ
ˆ
(2.0 4.0 ) m/s
v i j
 
1 s,
t

0
ˆ
ˆ
(2.0 2.0 ) m/s
v i j
 
2 s,
t

0
ˆ
ˆ
(2.0 0.0 ) m/s
v i j
 
3 s,
t

0
ˆ
ˆ
(2.0 2.0 ) m/s
v i j
 