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2D Projectile Motion
Concept Questions
CT2D1.
A projectile is fired at an angle
θ
with initial velocity v
0
from a table a height h above the
floor. The projectile strikes the floor with a final speed v given by the formula
.
What is the correct formula for v
x
?
A) v
0
cos
θ
B) v
0
sin
θ
C) Neither of these
Answer: v
ox
= v
0
cos
θ
. a
x
= 0 so v
x
is constant. Since v
x
is constant, its value at the end of
the flight is exactly the same as its value at the beginning of the flight, which is v
0
cos
θ
.
CT2D2
. A bullet is fired horizontally from a rifle on the Moon (where there is no air).
The initial speed of the bullet when it leaves the gun barrel is v
o
. Assume that the ground
is perfectly level (and endless).
Which one, if any, of the following three statements is
false
)
A ) During its entire flight, the minimum speed of the bullet is v
o.
B ) The acceleration of the bullet is constant during its flight.
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View Full DocumentC ) The time it takes for the bullet to hit the ground increases as v
o
is increased.
OR
D ) All of the above statements are true!
Answer: the time it takes for the bullet to hit the ground is independent of v
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 Fall '06
 DUBSON
 Physics, Projectile Motion

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