Answer:
7 seconds
Step-by-step explanation:
Ballistic motion is usually modeled in the vertical direction in US customary units by the equation h(t) = -16t^2 +v0·t +h0, where v0 and h0 are the initial velocity and height, and h(t) is the height as a function of time in seconds. For the given initial conditions, the equation of vertical motion will be ...
h(t) = -16t^2 +64t +336
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This question asks you for the value of t for which h(t) = 0. We can solve that equation by factoring.
0 = -16t^2 +64t +336
0 = t^2 -4t -21 . . . . . . . . divide by -16
0 = (t -7)(t +3) . . . . . . . factor the quadratic
t = 7 . . . . . . the positive value of t that makes the equation true
The ball will return to the ground after 7 seconds.
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<em>Additional comment</em>
A graph of the function reveals the ball reaches a maximum height of 400 feet after 2 seconds.
In metric units, the equation is h(t) = -4.9t^2 +v0·t +h0, where distances are in meters instead of feet. Time is still in seconds.
I wanna say 9.6 inches
Because 4 divided by 50 is 0.08 and 120 x 0.08 is 9.6
Answer: -3π/2
Step-by-step explanation:
The unit circle is tricky, but here are some things to know:
- When measuring angles, you usually move in the counter-clockwise direction. If you are moving clockwise (like shown in your picture), the angle will be negative.
- The unit circle is typically measured in radians, not degrees
- To convert from radians to degrees, multiply by 180/π
- To convert from degrees to radians, multiply by π/180
- The whole unit circle measures 2π (360 degrees). This means that the positive x-axis can be referred to as 0 or 2π, the positive y-axis is referred to as π/2, the negative x-axis is referred to as π, and the negative y-axis is referred to as 3π/2.
-If the angle is negative, switch the signs of the axis above.
The information above is all you need to answer the above question, but if you want/need anything else on the unit circle, just let me know.
3x - 5y = 18 over
-10x + 5y = 10
Add them because the 5y's have the right symbols for us to add
-7x = 28
Divide
x = -4
Now you can plug in -4 for x in one equation, I would use the first equation!
3(-4) - 5y = 18
-12 - 5y = 18
Add 12
-5y = 30
Divide
y = -6
Your solutions are going to be:
x = -4
y = -6
To check your work plug x and y into one equation:
3(-4) - 5(-6) = 18
-12 + 30 = 18
18 = 18
Since 18 does equal 18 you know that your solution's work!