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A football is kicked vertically upward from a height of 5 feet with an initial speed of 60 feet per second. The

formula h = 5 + 60t - 1612 describes the ball's height above the ground, h, in feet, t seconds after it was
kicked. Use this formula to find the ball's height 2 seconds after it was kicked.

The ball's height, 2 seconds after it was kicked, was [?] feet?

User MRu
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1 Answer

16 votes
16 votes

Answer: Are you sure you wrote out the formula correct? if so, then based of the formula, the answer is -1487. Since the question asks to use the formula, we end up with this answer. I am pretty sure your missing a variable or have missed typed the formula because a negative height isn't possible unless the force that was pushing the ball down was great enough that the second the ball flew up, it went flying down at incredible speed. One example of this is if you through a ball of a mountain up in the air, but the wind direction was going down. This would result in the ball going up for only measly second, then instantly dropping down on rapid speeds.

Explanation: Since we are already given all necessary values in the story problem, all that is left is to substitute into the formula and solve algebraically.

Step 1.) Gather what you know

(+) Formula for height; h=5+60t-1612

(+) We know we need to find the ball's height after 2 second's in air.

(+) h=height

(+) t = time

Step 2.) Understand what you need to do. Since the formula determines the height of the kicked object given the value of t (time), we need to substitute t with the value necessary to know how high the object will fly in that given time. In this story problem, it is asking us the ball's height in 2 seconds.

Notice: The object height is calculated by the speed of the object in the air + other variable which include the initial height of the object and more.

Step 3.) Use the formula and substitute. Since we know how the formula works, we know that if we substitue any t (time) in the formula, then it will give use the height based of the t (time) we have given.

1.) h = 5 + 60(t) - 1612

2.) h = 5 + 60(2) - 1612

Step 4.) Use Algebra to solve the equation.

1.) h = 5 + 60(2) - 1612

h = 5 + 120 - 1612

h = 125 - 1612

h = -1487

User Musecz
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