Answer:
- Josh's book lands first
- Ben's lands about 0.648 seconds later
Step-by-step explanation:
Using the given equation for v=60 and s=40, the height of Ben's book is ...
h(t) = -16t² +60t +40
We want to find t when h(t) = 0, so we're looking for the solution to ....
0 = -16t² +60t +40
Using the quadratic formula, we find the positive value of t to be ...
t = (-60 -√(60² -4(-16)(40)))/(2(-16)) = (15 +√385)/8 ≈ 4.3277
__
Similarly, the height of Josh's book is ...
0 = -16t² +48t +40
t = (-48 -√(48² -4(-16)(40)))/(2(-16)) = (12 +√304)/8 ≈ 3.6794
__
The time before Josh's book lands is shorter by ...
4.3277 -3.6794 ≈ 0.6482 . . . . . seconds
Josh's book reaches the ground first, by about 0.648 seconds.
Answer:

Step-by-step explanation:
Look at the picture.
The formula of an area of a triangle:

<em>b</em><em> - base</em>
<em>h</em><em> - height</em>
<em />
We need a length of a height.
Use the Pythagorean theorem:

We have:

Substitute:

<em>subtract 25 from both sides</em>

Calculate the area:

From here, just make it inverse:

Answer:
2/5
Step-by-step explanation:
2/3 of 3/5 means to multiply the fractions to get 6/15
6/15 can be reduced by dividing by 3 to get 2/5
Answer:
b i think
Step-by-step explanation: