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8 votes
8 votes
Independent Practice

Use the vertical motion formula h = –16t2 + vt + c.


A soccer ball is kicked with a starting upward velocity of 50 ft/s from a starting height of 3.5 ft. Substitute the values into the vertical motion formula and let h = 0. Use the quadratic formula to solve for t. If no one touches the ball, how long is the ball in the air?


A.
0.1 s


B.
–0.1 s


C.
3.2 s


D.
1.1 s

User Tiddly
by
2.6k points

2 Answers

18 votes
18 votes

Answer:



Explanation:

User Jkerian
by
2.9k points
14 votes
14 votes

Answer: The answer is letter A. 0.1s...... I think

-16t^2 + 50t + 3.5= 0

Step-by-step explanation: The answer is either letter A or letter B

Question

Use the vertical motion formula h=-16 t^{2}+v t+ch=−16t

2

+vt+c. A soccer ball is kicked with a starting upward velocity of 50 ft/s from a starting height of 3.5 ft. Substitute the values into the vertical motion formula Let h = 0.

Explanation

Step 1

1 of 2

The starting velocity is 50 ft/s ,when the ball is 3.5 ft high

So, v=50v=50 , h=3.5h=3.5 , t=0t=0

\begin{align*} h&=-16t^2+vt+c &&\text{{\color{#c34632}The vertical motion formula}}\\\\ 3.5&=-16(0)^2+50(0)+c &&\text{{\color{#c34632}Substitute 3.5 for $h$ , 50 for $v$ , 0 for $t$}}\\\\ c&=3.5 &&\text{{\color{#c34632}Simplify}}\\\\ \end{align*}

h

3.5

c

=−16t

2

+vt+c

=−16(0)

2

+50(0)+c

=3.5

The vertical motion formula

Substitute 3.5 for h , 50 for v , 0 for t

Simplify

So, the vertical motion formula will be

h= -16t^2 + 50t + 3.5

Let h= 0

-16t^2 + 50t + 3.5= 0

User Arif Fikri Abas
by
2.6k points