About 4.1 seconds. How long was the ball in the air? We are told that t represents time in seconds since the ball was thrown, so it started to be 'in the air' at t = 0 To answer the question, then, we need to know the time when it stopped being in the air. We are told that the ball hit the ground. So that's what happened when it stopped being airborne. We need to relate that event to the mathematics we're working with. What can we say about h , the height of the ball when the ball hits the ground? Answer: The height will be 0 when the ball stops being in the air. Now translate this back to the mathematics: The ball is in the air from t = 0 until the time t when h = 0 . Find the time t that makes h = 0 . That means: solve: − 5 t 2 + 20 t + 2 = 0 We can solve this by solving: 5 t 2 − 20 t − 2 = 0 (Either multiply both sides of the equation by − 1 , or add 5 x 2 − 20 x and − 2 to both sides and then re-write it the other way around) That's a quadratic equation, so try to factor first. But don't spend too much time trying to factor, because not every quadratic is easily factorable and that's OK, because we still have the quadratic formula if we need it. We do need it. t = − ( − 20 ) ± √ ( − 20 ) 2 − 4 ( 5 ) ( − 2 ) 2 ( 5 ) = 20 ± √ 440 10 = 20 ± √ 4 ( 110 ) 10 = 20 ± 2 √ 110 10 = 2 ( 10 ± √ 110 ) 2 ( 5 ) = 10 ± √ 110 5 We can see that 10 < √ 110 < 11 . In fact ( 10 + 1 2 ) 2 = 10 2 + 10 + 1 4 = 110.25 Using 10.25 as an approximation for √ 110 , we get : for the solution t = 10 − √ 110 5 we'll get a negative t . That doesn't make sense. The other solution gives t ≈ 10 + 10.25 5 = 20.5 5 = 4.1 seconds. So the ball was in the air from t = 0 until about t = 4.1 . The elapsed time is the difference, 4.1 seconds.
Answer:
17. surface area ≈ 441.84
04π m² or 1387.38 m²
18. Ratio of volumes = 8/27
19. volume of the smaller solid = 339 yards³
Step-by-step explanation:
17 .
To find the surface area of the sphere we have to find the radius of the sphere first.
volume of a sphere = 4/3πr³
volume = 1548π m³
r = ?
volume of a sphere = 4/3πr³
1548π = 4/3 × π × r³
multiply both sides by 3/4
1548π × 3/4 = πr³
4644π/4 = πr³
1161π = πr³
divide both sides by π
r³ = 1161
cube root both sides
r = ∛1161
r = 10.5101942
r ≈ 10. 51
surface area of a sphere = 4πr²
surface area = 4 × π × 10.51²
surface area = 4 × 110.4601 × π
surface area = 441.8404π m²
surface area = 441.8404 × 3.14 = 1387.378856 m² ≈ 1387.38 m²
18
If two figure or solid are similar with scale factor or ratio of x/y then the ratio of their volume is (x/y)³. If the ratio of of two similar prism is 2 : 3 the volume will be (2/3)³ = 8/27 .
19
If two solids are similar then the ratio of their surface area is the squared of the scale factor.
121/361 = (x/y)²
square root both sides
x/y = 11/19
If two solids are similar then the ratio of their volume is the cube of the scale factor.
(11/19)³ = a/1747
1331/6859 = a/1747
cross multiply
6859a = 2325257
divide both sides by 6859
a = 2325257/6859
a = 339.008164455
a ≈ 339 yards³
volume of the smaller solid ≈ 339 yards³
Answer:
8 in
Step-by-step explanation:
because 4 x 2 = 8 inches squared
Answer:

Because the 
The integral converges to 
Step-by-step explanation:
For this case we want to find the following integral:

And we can solve the integral on this way:


And if we evaluate the integral using the fundamental theorem of calculus we got:

Because the 
The integral converges to 
Answer:
15
Step-by-step explanation:
the triangles are similar so will be the same proprotion,
I have attached a picture showing how I solved this. the second traingle is 3 times as large (15 by 12) compared to the first triangle which is 4 by 5.