l>Practice 2F

Practice 2F: | 1 | 2| 3 | 4 | 5 | 6| go upFalling thing - by Kevin Bailey & Chicken Breast,2002

1. A robot probe autumn a camera off the pickled in salt of a 239 mhigh cliff top top Mars, wherein the free-fall acceleration is -3.7 m/s2.

You are watching: Maria throws an apple vertically upward from

a. Uncover the time forced for the camera to reachthe ground.

b. Discover the velocity with which it access time theground.

Ahhh, those stunner robots from the future. Always hijacking NASA"s rockets, travel to Mars, and dropping federal government property off cliffs in ~ a slower acceleration 보다 Earth.

Any who, if you wish to uncover the time, just talk come pooh, he"ll call you. Dx = vi(Dt) + 1/2a(Dt)2

Dx = 239 m

by means of = 0 m/s

Dt = ???

vf = ???

a = -3.7 m/s2

So, (239 m) = (0 m/s)(Dt) + 1/2(-3.7m/s2)(Dt)2 and (Dt)= 11.4 s oH yes LiFe Is SwEeT

Furthermore, if you wish to find the last velocity just use vf = vi+ a(Dt)

Dx = 239 m

by means of = 0 m/s

Dt = 11.4 s

vf = ???

a = -3.7 m/s2

So, (vf) = (0 m/s) + (-3.7 m/s2)(11.4s) = -42.18 m/s or -42.1 m/s

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2. A flowerpot falls from a windowsill 25.0 m above thesidewalk.

a. How quick is the flowerpot relocating when itstrikes the ground?

b. Just how much time does a passerby ~ above the sidewalkbelow have to move out of the way before the flowerpot access time the ground?

Boy, Isure hope that the bad passerby doesn"t get hit!

Yeah, fine I"m simply gonna perform this one backwards. Time first. Dx = vi(Dt) + 1/2a(Dt)2

Dx = 25 m

vi = 0 m/s

Dt = ???

vf = ???

a = -9.8 m/s2

So, (25 m) = (0 m/s)(Dt) + 1/2(-9.8m/s2)(Dt)2 and also (Dt)= 2.26 s Chicken Breast

Furthermore, if you great to discover the final velocity simply use vf = vi+ a(Dt)

Dx = 25 m

using = 0 m/s

Dt = 2.26 s

vf = ???

a = -9.8 m/s2

So, (vf) = (0 m/s) + (-9.8 m/s2)(2.26s) = -22.1 m/s

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3.A tennis round is thrown vertically upward with aninitial velocity of +0.80 m.

a. What will certainly the ball"s speed be once it returnsto its starting point?

b. Just how long will certainly the round take to with itsstarting point?

So, what we have here is yes, really 2 equations. 1 ~ above the method up, and also 1 ~ above the method down. BUT, because TIME IS ~ above BOTH SIDES...that"s right, the takes simply as lengthy to go up as down, we will simply solve for up and double. Usage vf = using + a(Dt)

Dx = ???

by means of = 8.0 m/s

Dt = ???

vf = 0 m/s

a = -9.8 m/s2

So, (0 m/s) = (8.0 m/s) + (-9.8 m/s2)(Dt) so Dt = 1.63 s Don"t forget to double it!

OH yeah, and component A. Well, ns think the -8.0 m/s, the exact same as the equal however opposite velocity together the starting one ns think is pretty much self explanitory.

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4. Stephanie hits a volleyball indigenous a elevation of 0.80 mand provides it an initial velocity the +7.5 m/s right up.

a. Just how high will the volleyball go?

b. Exactly how long will it take the sphere to reach itsmaximum height? (Hint: in ~ maximum height, v = 0 m/s)

Humm...this is a tricky one. In order to find the displacement you require to know this formula. Vf2 = vi2 + 2a(Dx), where:

Dx = ???

through = 7.5 m/s

Dt = ???

vf = 0 m/s

a = -9.8 m/s2

So just plug in the numbers and let that magical math machine do the rest!

(0 m/s)2 = (7.5 m/s)2 + 2(-9.8 m/s2)(Dx) so Dx = 2.87 m

Ok, and for the next component you will certainly take heed come the hint, and use the formula vf = by means of + a(Dt)

Dx = 2.87 m

by means of = 7.5 m/s

Dt = ???

vf = 0 m/s

a = -9.8 m/s2

so again, just plug in the numbers and let that magical math machine do the rest!

(0 m/s) = (7.5 m/s) + (-9.8 m/s2)(Dt) for this reason Dt = .765 s

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5. Maria throws an apologize vertically increase from a heightof 1.3 m through an early stage velocity that +2.4 m/s.

a. Will certainly the apple with a girlfriend in a treehouse 5.3 mabove the ground?

b. If the apologize is no caught, exactly how long will certainly the applebe in the air prior to it access time the ground?

Who execute you suppose developed that treehouse?

This inquiry is usually a quite clever means to ask for the height. Don"t forget to subtract Maria"s 1.3 m height! usage the complying with formula. Vf2 = vi2 + 2a(Dx), where:

Dx = ???

using = 2.4 m/s

Dt = ???

vf = 0 m/s

a = -9.8 m/s2

Uh oh, ns hear that acquainted chomping sound of the math Robot coming again! Don"t worry, just plug and chicken breast it.

(0 m/s)2 = (2.4 m/s)2 + 2(-9.8 m/s2)(??? m) so height = .29 m + 1.3 m = 1.6 m NO, WON"T REACH

Well remember for the second component that time is on both sides, that takes just as lengthy to go up together down, us will simply solve because that up and also double. Use vf = through + a(Dt)

Dx = ???

vi =2.4 m/s

Dt = ???

vf = 0 m/s

a = -9.8 m/s2

So, (0 m/s) = (2.4 m/s) + (-9.8 m/s2)(Dt) for this reason Dt = .4897959 s Don"t forget to dual it! yet we"re no done. The apple began at 1.3 m, so we still have that much farther to fall.

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Dx = 1.3 m

by means of =-2.4 m/s

Dt = ???

vf = ??? m/s

a = -9.8 m/s2

So utilizing Dx = vi(Dt) + 1/2a(Dt)2 then (1.3 m) = (2.4 m/s)(Dt) + 1/2(-9.8)(Dt)2

Dt = .82 s

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6. Calculation the displacement that the volleyball in sampleProblem 2F once the volleyball"s final velocity is 1.1 m/s upward.