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calculusxy
 one year ago
MEDAL!!!
A ball is thrown straight up. What will be the instantaneous velocity at the top of its path? What will be its acceleration at the top? Why are your answers different?
calculusxy
 one year ago
MEDAL!!! A ball is thrown straight up. What will be the instantaneous velocity at the top of its path? What will be its acceleration at the top? Why are your answers different?

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anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Is it not that when it goes upward, at the top of its path, velocity =0?

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.3OOOPS is correct Gravity is pulling the ball down. The initial throw pushes the ball up and the velocity decreases as the ball climbs higher because it's fighting gravity. Once the ball gets to the peak, the velocity hits 0. The acceleration due to gravity is always the same no matter how fast the ball is moving.

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0What would be its acceleration?

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.3The acceleration due to gravity is always the same no matter how fast the ball is moving. acceleration of gravity = 9.8 m/s^2 = 32 ft/s^2 (both are approximate)

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0How did you calculate that 9.8m/s^2 = 38ft?s^2 ?

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.3the acceleration of gravity only changes when the height is drastically different technically there is change, but it's so small that it's hard to notice

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.3it's just something you look up in a table, book, or something. or you memorize it

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0I mean i know that 9.8m/s^2 is the instantaneous speed of a freefalling object. but how did you just calculate the acceleration at the top? acceleration = gravity x time ?

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.3the acceleration is equal to the acceleration of gravity

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0Honestly, i have no idea to what you just said.

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.3imagine the object in free fall every second, the speed increases by 9.8 m/s

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.3let t be the time elapsed since dropping the object and letting it free fall (ignore air resistance) t = 0 speed = 0 m/s t = 1 speed = 9.8 m/s t = 2 speed = 19.6 m/s (9.8 times 2 = 19.6) t = 3 speed = 29.4 m/s (9.8 times 3 = 29.4) etc etc

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0so what's going to happen next?

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.3No matter where the object is, it's feeling the same force on it. So it undergoes the same acceleration throughout its journey going up and then coming back down

zzr0ck3r
 one year ago
Best ResponseYou've already chosen the best response.0acceleration is a vector. i.e. it has direction.

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0but my question was how did you get this: "acceleration of gravity = 9.8 m/s^2 = 32 ft/s^2 (both are approximate)"

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.3Galileo discovered it long before Newton, but yeah pretty much

zzr0ck3r
 one year ago
Best ResponseYou've already chosen the best response.0did he discover the speed or just the thing?

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.3those two numbers are constants that you memorize or look up

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0so the acceleration is 32?

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.332 ft per s^2, yes

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.3just the speed/acceleration I think @zzr0ck3r I don't think he actually came up with unifying theories like Newton did

zzr0ck3r
 one year ago
Best ResponseYou've already chosen the best response.0And almost got killed as a result. Ahh humans...

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0so i found this website where it said that the acceleration can just be defined as "g", i believe:

zzr0ck3r
 one year ago
Best ResponseYou've already chosen the best response.0yes. gravity is constant and we normally just say g because we are estimating it when we give an actually number.

zzr0ck3r
 one year ago
Best ResponseYou've already chosen the best response.0like \(\pi\) and 3.14. They are not the same but we use 3.14 when we need a close number.

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.3g = 9.8 m/s^2 or g = 32 ft/s^2 both are the same. Saying 'g' is a shorthand way to say "acceleration of gravity on earth at sea level"

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.3When you hear things like "the rocket is going 3 g's (idk I made up the number)" it means "the rocket is accelerating 3 times the acceleration of gravity" so the rocket's acceleration would be 29 m/s^2

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0Thank you. I have another question.

phi
 one year ago
Best ResponseYou've already chosen the best response.0If you have time and are interested, see https://www.khanacademy.org/science/physics/newtongravitation/gravitynewtonian/v/introductiontogravity

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0If a salmon swims straight upward in the water fast enough to break through the surface at a speed of 5m/s, how high can it jump above the water?

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.3Acceleration of gravity: g = 9.8 m/s^2 Initial Velocity Vo = 5 m/s Plug those values into h = (g/2)t^2 + Vo*t We don't know anything about the angle in which it jumps, so ignore that. Assume it jumps straight up. Find the vertex to get the answer.

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0h = (9.8/2)5^2 + 5*2

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.3t is unknown for now

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0Yeah that's what I was guessing

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.3you should get h = 4.9t^2 + 5t find the vertex of this to figure out the highest point

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0How would I figured out the vertex?

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.3h = 4.9t^2 + 5t is in the form h = at^2 + bt + c a = 4.9 b = 5 c = 0 plug the values of 'a' and 'b' into b/(2a) to figure out the time value at the peak once you get this value, plug it into h = 4.9t^2 + 5t to find h

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0so t would be b/(2a) ?

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.3the t value at the peak, yes dw:1436315387333:dw

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.3then you plug t = 0.51 into h = 4.9t^2 + 5t

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.04.9(0.51)^2 + 5(0.51) 4.9(0.2601) + 5(0.51) 1.27449 + 2.55 3.82449

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.3Yep, 1.27551 the max height is roughly 1.27551 meters and this happens at around 0.51 seconds

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0Thank you! This is a worksheet, so can u make sure all of my answers? I will post them in another post.

calculusxy
 one year ago
Best ResponseYou've already chosen the best response.0It's like 5 questions?

jim_thompson5910
 one year ago
Best ResponseYou've already chosen the best response.3ok make a brand new post
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