Recitation 05 Ch. 10 PDF

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Summary

Recitation project done week 5 chapter 10...

Description

Recitation05: Ch. 10

Manager:

PHYS 170: Electricity and Motion

Presenter:

Manages the group. Ensures that members are fulfilling Presents oral reports to the class for the group at the end of their roles and the assigned tasks are being accomplished each class. on time, and all members of the group are participating in the activities and understanding the concepts. Records the names and roles of the group members at the beginning of each day. Records the important aspects of the group discussions, observations, insights, etc.

Reflector: (Optional) Observes/comments on the group dynamics and behavior with respect to the learning process. The reflector must take notes (see end of document) about how well the group is operating (or what needs improvement) and why.

Instructions: Read and print out this document prior to attending recitation. Choose your appropriate role based on your role last week (Manager → Presenter → Recorder → Reflector). As a group, work on the following questions for 30 min. At that point, the presenter will present your answer to one question to the class. Hand in one copy of this document per group at the end of recitation. 1) When a quarterback throws a football, what forces act on the football while it moves through the air? You can ignore air resistance. Explain your answer and include the direction(s) in which these forces act. (**Possible presentation question.**)

The forces that acts on the football while it moves through the air is a net force in the direction it was thrown and with gravity acting on it making it a downward motion.

PHYS 170: Electricity and Motion Recitation05: Ch. 10

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2) When you launch something horizontally off a cliff, what is its acceleration in the xdirection? Support your answer with Newton’s First or Second Laws of motion. (**Possible presentation question.**)

No acceleration in the horizontal direction following the Newton’s First Law, since the object is already in the air it will continue to move due to the downward force of gravity acting on the ball moving in an x direction..

3) When you launch something horizontally off a cliff, what is its acceleration in the ydirection? Support your answer with Newton’s First or Second Laws of motion. (**Possible presentation question.**)

It starts at 0, and doesn’t move until force of gravity acts upon it, as it launches

4) When you launch something horizontally off of a cliff, how much of that initial velocity is in the x-direction? a) All of it b) None of it c) Some of it d) Depends

5) When you launch something horizontally off of a cliff, how much of that initial velocity is in the y-direction? (**Possible presentation question.**) a) All of it b) None of it c) Some of it d) Depends

PHYS 170: Electricity and Motion Recitation05: Ch. 10

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6) When you throw an object up at an angle, what is its acceleration in the y-direction at the very top of its motion? a) zero b) -10 m/s2 c) It’s equal to the initial velocity d) It’s equal to the final velocity 7) When you throw an object up at an angle, what is its acceleration in the x-direction at the very top of its motion? (**Possible presentation question.**) a) zero b) -10 m/s2 c) It’s equal to the initial velocity d) It’s equal to the final velocity 8) Since the Moon is constantly attracted toward the Earth by their gravitational interaction, why doesn’t it crash into the Earth?

Because of the difference in mass between the Moon and the Earth, the forces become equal and opposite causing the gravitational pull between the moon and the earth to not crash.

9) Suppose you roll a ball off a tabletop. Will the time to hit the floor depend on the speed of the ball? (Will a fast ball take a longer time to hit the floor?) If not, what measurable effect will a faster ball have? Defend your answers. (**Possible presentation question.**) The speed, force, and mass will not matter, it would take the same amount of time for the object to hit the ground if it is dropped straight down from a table top and rolled off a table top, instead it will depend on the gravity. All of the velocity will be acting on it in a horizontal direction, whereas it will go in a downward direction, since the intitial position is at 0.

10) Two golfers each hit a ball at the same speed, but one at 60° above the horizontal and the other at 30° above the horizontal. Which ball goes farther (horizontally)? Which hits the ground first? Ignore air resistance. Justify your answers. (**Possible presentation question.**) Both balls will land at the same time because they were both hit at the complimentary 90 degree angle, while the 30 degree ball will hit the ground first

PHYS 170: Electricity and Motion Recitation05: Ch. 10

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11) You’re in an airplane that flies horizontally with a speed of 280 m/s when an engine falls off. Ignore air resistance and assume it takes 30 s for the engine to hit the ground. a) What was the altitude of this airplane? ½(g*t^2) =4500 b) How far does the aircraft engine move horizontally while it’s falling? 280*30=8400

Reflector Notes: (Observe and comment on the group dynamics and behavior with respect to the learning process. How well the group is operating or what needs improvement and why?)

Even though we struggled a lot, we all did research and looked up notes and contributed knoweledge and tried to figure out the answers. We always work well together and figure it out and catch each other up, if someone doesn’t understand a quesiton.

PHYS 170: Electricity and Motion Recitation05: Ch. 10

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