Given :
As a plane takes off it ascends at a 20 degree angle of elevation.
If the plane has been travelling at an average rate of 290 ft/s and continues to ascend at the same angle.
To Find :
How high is the plane after 10 seconds.
Solution :
Distance travelled by plane, D = 2900 ft.
Angle of elevation, Ф = 20°.
Height gained is given by :

H = 2900 × sin 20°
H = 991.86 ft.
Therefore, height of plane after 10 seconds is 991.86 ft.
Hence, this is the required solution.
Answer:
Step-by-step explanation:
It will just be 12, since the uncles can go in one group and fit 12 uncles, and than the aunts can get photographed in 2 groups that add up to 12
The answer is 20x^18 which is the last option.
Answer:
42
Step-by-step explanation:
Answer:
8.2 *10^5 ft lb
Step-by-step explanation:
Wcoal = 800*500 = 400000 = 4*10^5 ft lb

Using a right Riemann sum
The width of the entire region to be estimated = 400 - 0 = 400
Considering 8 equal subdivisions, then the width of each rectangular division is 400/8 = 50
F(x) = 6(400-y)
![\left[\begin{array}{cccccccccc}x&0&50&100&150&200&250&300&350 &400\\f(x)&2400&2100&1800&1500&1200&900&600&300&0\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcccccccccc%7Dx%260%2650%26100%26150%26200%26250%26300%26350%20%26400%5C%5Cf%28x%29%262400%262100%261800%261500%261200%26900%26600%26300%260%5Cend%7Barray%7D%5Cright%5D)
Wrope = 50(2100) + 50(1800) + 50(1500) + 50(1200) + 50(900) + 50(600)
+ 50(300) + 50(0) = 420000 = 4.2 * 10^5 ft lb
Note: Riemann sum is an approximation, so may not give a accurate value
work done = Wcoal + Wrope= 4*10^5+ 4.2 * 10^5 = 8.2 *10^5 ft lb