Answer:
Step-by-step explanation:
If you complete the square and double the time to get back to the surface you will have your answer.
d = 2(t^2 - 4t) - 10; Take 1/2 of - 4 and square it. Add the result inside the brackets.
d = 2(t^2 - 4t + (4/2)^2 ) - 10
d = 2*(t^2 - 4t + 4) - 10 - 2*4
Did you notice I put the 2*4 outside the brackets and turned it into a minus. The reason that happened is to offset what is inside the brackets that was added here.
d = 2(x - 2)^2 - 18; t^2 - 4t + 4 is a perfect square. that 2 inside the brackets is critically important.
The 18 is the maximum depth below the surface of the water. (Poor choice of words. Technically - 18 is a minimum). But you want to use t - 2 to make it into 0. t - 2 = 0 ; t =2
What that means is that it took 2 minutes to get 18 meters below the surface of the water. He will break the surface of the water 2 minutes later. I don't exactly know how to answer the question. It is 2 minutes to get from the minimum depth to the surface. It is 4 minutes to get to the surface when he begins his dive.
Answer:
1500 Time the multiple of model scale is the actual length of the ramp.
Step-by-step explanation:
Given:
Actual length of ramp is 500ft
Modelling scale is 1/125.
To Find:
how many times as long as the actual on ramp is the model.
Solution:
Actual length is 500 ft
When Civil engineer is modelling the ramp on model then it is about 1/125 of the actual length present at that site.
So
=500*1/125
=4 inches
So on model scale engineer took inches as a unit for scale.
Actual length is 500 ft and model length is 4 inches
So 1 ft corresponds to 12 inches hence 500*12=6000 inches
6000 inches corresponds to 4 inches on model scale
i.e it is about 1500 time multiple of the model scale.
Answer:
218
Step-by-step explanation:
first find the area of the circle-
to find the area of the triangle, we need the base and the height. The base we know is 16, since we don't know the height yet, use the Pythagorean theorem to find the height. One leg is 16 the hypotenuse is 20 (2* the radius).
Now I know the height is 12. Find the area of the triangle
subtract the area of the triangle from the area of the circle
314-96=218