A hot-air balloon left the ground rising at 5 ft per second. 13 seconds later, Victoria through a ball straight up to her friend Colleen in the balloon. At what speed did she throw the ball if it just made it to Colleen?
Work so far, but I am a little lost with this problem.
A hot-air balloon left the ground rising at 5 ft per second.
13 seconds later, Victoria through a ball straight up to her friend Colleen in the balloon.
At what speed did she throw the ball if it just made it to Colleen?
got this problem wrong so here it is again but with number change.
A hot-air balloon left the ground rising at 4 ft per second. 10 seconds later, Victoria through a ball straight up to her friend Colleen in the balloon. At what speed did she throw the ball if it just made it to Colleen?
been trying to figure out how they got 69.692. if i figure this out i will be able to use this and do the problem again that i posted that use different numbers.
original problem
A hot-air balloon left the ground rising at 5 ft per second. 13 seconds later, Victoria through a ball straight up to her friend Colleen in the balloon. At what speed did she throw the ball if it just made it to Colleen?
A hot-air balloon left the ground rising at 5 ft per second.
13 seconds later, Victoria through a ball straight up to her friend Colleen in the balloon.
At what speed did she throw the ball if it just made it to Colleen?
now i understand how they got 69.692. like previously stated it took one second to reach colleen but wont. and the reason is that the balloon rose another 5 feet hence again will not reach her. so for it to do that the ball should be thrown at 64.692 + 5 will give you 69.692 must be thrown initially to reach Colleen in time.
Here is my problem same type with different number will report back with my work shortly.
A hot-air balloon left the ground rising at 4 ft per second. 10 seconds later, Victoria through a ball straight up to her friend Colleen in the balloon. At what speed did she throw the ball if it just made it to Colleen?
A hot-air balloon left the ground rising at 5 ft per second.
13 seconds later, Victoria through a ball straight up to her friend Colleen in the balloon.
At what speed did she throw the ball if it just made it to Colleen?
A hot-air balloon left the ground rising at 4 ft per second. 10 seconds later, Victoria through a ball straight up to her friend Colleen in the balloon. At what speed did she throw the ball if it just made it to Colleen?
The height of the ball is given by: .h=vot−16t2 . . where vo is the initial speed of the ball.
10 seconds later, Colleen is 40 feet above the ground.
Since the ball just makes it to Colleen, the maximum height of the ball is 40 feet.
The maximum height occurs at the vertex of the parabolic function.
The vertex is at: t=2a-b, where b=vo and a=-16
Maximum height occurs at: t=2(-16)-vo=32vo seconds.
Hence, maximum height is: h=vo(32vo)−16(32vo)2=64vo2 feet.
We have: 64vo2=40⇒vo=64⋅40⇒v=840
Therefore, the ball should be thrown at: 50.59644256≈50.596 ft/sec
Needs to be rounded off at three decimal places.
Since it took about 1 second to get to Colleen it rose another 4 feet.
So in order to reach Colleen the ball must be thrown at a speed of 54.596 feet per second.
NOTE: from the last problem 64.7 was used how was that figure out? 64.7 + 5 = 69.7. The answer to the original problem i started with was 69.692 feet per second in order to reach Colleen.
i just dont understand how they ge their answer bugs me a lot. i know how to do the problem but simply for the love of god cant see where 54.754 came from. :evil:
As a matter of fact, a little while ago I found this exact problem and it agreed with our answer. That is what made me wonder about the answer you were given.
i emailed my professor telling him the situation with this problem. hopefully he will give me credit for it. did it twice and still got it wrong. BS if u ask me. i will post what he tells me.
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