We have been given that Sandra throws an object straight up into the air with initial velocity of 38 ft per second from platform that is 30 ft above the ground.

To find the time it will take for object to hit the ground, we will use formula:

$h(t)=-16t^2+v_0t+h_0$ , where, $v_0$ represents initial velocity and $h_0$ represents initial height.

Upon substituting our given initial velocity and initial height, we will get:

$h(t)=-16t^2+38t+30$

We know that object will hit the ground, when height will be 0, so we will equate object's height equal to 0 and solve for t as:

$-16t^2+38t+30=0$

Divide by 2:

$-8t^2+19t+15=0$

Upon using quadratic formula, we will get:

$t=\frac{-b\pm\sqrt{b^2-4ac}}{2a}=\frac{-19\pm\sqrt{19^2-4(-8)(15)}}{2(-8)}$

$t=\frac{-19\pm\sqrt{361+480}}{-16}=\frac{-19\pm\sqrt{841}}{-16}$

$t=\frac{-19\pm29}{-16}$

$t=\frac{-19-29}{-16},t=\frac{-19+29}{-16}$

$t=\frac{-48}{-16},t=\frac{10}{-16}$

$t=3,t=-\frac{5}{8}$

Since time cannot be negative, therefore, it will take 3 seconds for object to hit the ground.

7 0

2 years ago

Are 17 heartbeats in 15 seconds and 68 heartbeats in 60 seconds Equivalent

Andre45 [30]

Answer:

1.133.

Step-by-step explanation:

Yes because if you divide 17 by 15 you get about 1.133 and if you divide 68 by 60 you also get about 1.133.

4 0

2 years ago

Read 2 more answers

10000= 10x10×_x_i need helo solving pls​

10000= 10x10×_x_i need helo solving pls