PHY 121 Exam 1 Conceptual Review PDF

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Draw graph on paper

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*1A

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*2. A.

D>A>B=C>F>E (A is 5 units, B and C are 3.75 units, D is 7.5 units, E is 0 units, F is 2.5 units)

E>C>B=D>F>A (A is 1 m/s, B is 13 m/s, C is -15 m/s, D is -13 m/s, E is -17 m/s, F is 9 m/s)

*Alisa is correct: answer 1.

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*D. is correct, launch speed is 2.94 m/s

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From most positive to most negative: C, B=D, F, A=E

See solution on next slide.

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*Answer 1. A > B

B>A=D>C=E>F (Tension values: A =3ma, B=4ma, C=2ma, D=3ma, E=2ma, F=ma)

B=E>C>D=F>A A=0, B=[(mgsin28)-4] newtons, C = =[(mgsin20)-4] newtons, D = 4 newtons, E = =[(mgsin28)-4] newtons, F = 4 newtons

Answer: Force of the earth (gravity) downward, force of the surface (aka normal) upward, force of push to the left—here I assumed no frictional force, but if there were one it would act to the left MC: D

Answer: Force of the earth (gravity) downward ONLY MC: D

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a. 20 N downward by Ns 3rd Law b. 5 N downward or book would accelerate c. 5 N upward by Ns 3rd Law

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Answer: There will be a downward gravitational force from the earth and an upward force from the floor acting on the man. The upward force must be larger because the man accelerates upward. Using ∑F = ma will yield that the force of the floor is therefore 1020N.

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