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```AP Physics 1 Choice board review (Tic –Tac –Toe)
Complete any three assignment in a straight line (Tic-tac-toe) to earn credit. Complete two additional assignments to replace one of your missing Lab or Quiz grade. Write
answers on a separate sheet of paper
Force: A fire helicopter carries a 620 kg bucket of
water at the end of a 20 m-long cable as it flies back
from a fire at a constant speed of 40 m/s. Air
resistance acts opposite to the helicopter’s horizontal
motion, causing the cable to hang at an angle of 40o
with respect to the vertical.
On the dot below that represents the bucket, draw and
label the forces (not components) that act on the
bucket.
Motion Graphs: Consider the position-time graph
shown above.
a.
Calculate the object’s instantaneous speed at time t
= 4 s. Also explain in a sentence why you used
that particular calculational method.
b. Calculate the force exerted by air resistance on the
bucket.
c. Calculate the tension in the cable. If you need to
draw anything other than what you have shown in part
(a) to assist in your solution, use the space below. Do
NOT add anything to the figure in part (a).
Gravity: A geosynchronous satellite, which always
remains above the same point on a planet’s equator, is
put in orbit around Jupiter to study that planet’s red
spot. Jupiter rotates once every 9.9 h.
2D problem: A brick is thrown upward from the top
of a building at an angle of 25o to the horizontal and
with an initial speed of 15 m/s. The brick hits the
ground after 3.5 s of flight.
Calculate the height of the building. [Label all
kinematics charts clearly.]
Calculate the radius of the satellite’s orbit.
b.
Answer first in terms of given variables and
fundamental constants.
c. Make an order-of-magnitude estimate of the answer.
a. Which ball hits the ground first? To answer, first
derive an expression for the time the blue ball was in
the air, or make up values and solve for the time each
reference to this result.
b. Which ball has a larger speed upon hitting the
b. What familiar object might reasonably perform this
the distances and times indicated on the graph’s axes.
c.
Describe in words, as you would to a non-physicist,
how this object moves. Justify your description
with facts from the fact sheet.
a.
Projectile: Two balls, identical except for color, are
projected horizontally from the roof of a tall building
at the same instant. The initial speed of the red ball is
twice the initial speed of the blue ball.
c.
On level ground, how much farther horizontally can a
person jump on the moon as compared to the earth if the
takeoff speed and angle are the same? The free-fall
acceleration on the moon is one-sixth what it is on earth.
To answer, first derive an expression for the distance a
person jumps on level ground, or make up values and solve
for the distance on Earth and the moon. Then justify your
Two body Problem: A 500 g block is released from rest on
a frictionless surface. It is connected by a light string over a
pulley to a 300 g hanging object, as shown above.
Draw and label the forces (not components) that act on each
block.
d. Determine a value for this altitude to two digits.
500 g block
300 g object
Is the net force acting on the 500 g block greater than, less
Uniform Circular Motion:
Go to the following link Uniform Circular Motion
Vertical Circle and use the information to answer the
following question.
Consider a 1-kg brick being whirled in a vertical circle at
the end of a 1-meter rope.
What critical velocity must the brick achieve in
order to pass safely through the top of its circular path?
What is the tension in the rope as it is passing
through the top of its circular path?
How would be the critical velocity of the brick if it
were to be whirled on the moon where acceleration
due to gravity is 1/6th that on earth?
Impulse:
Rocket Launch:
A model rocket of mass 0.25 kg is launched vertically
with an engine that is ignited at time t = 0, as shown
above. The engine provides a force of 10 N by firing
for 2.0 s. Upon reaching its maximum height, the
rocket deploys a parachute, and then descends
vertically to the ground.
1. Draw a free-body diagram for the following situations:
An estimated force vs. time curve for a ball struck by a bat is
i)while the engine is firing up
shown in the figure above.
ii) After the engine stops but before the parachute is deployed
a.
Calculate the impulse delivered by the bat to the
ball.
2. Determine the amount of the rocket’s acceleration during
b. This 0.25 kg ball was initially moving toward the
the 2 s firing of the engine.
bat at a speed of 20 m/s. Calculate the exit speed
of the ball. Annotate your calculation with a