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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 ball is in the air. Then justify your answer with reference to this result. b. Which ball has a larger speed upon hitting the ground? Justify your answer. b. What familiar object might reasonably perform this motion? Justify your answer with specific reference to 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 answer with specific reference to your calculations. 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 than, or equal to 3.0 N? Justify your answer. 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 description of your approach.