<span>3/30 = n/50
</span><span>1/10 = n/50
10n = 50
n = 50/10
n=5</span>
9514 1404 393
Answer:
- boat: 72 km/h
- current: 16 km/h
Step-by-step explanation:
The speed difference between boat and current is the upstream rate:
(448 km)/(8 h) = 56 km/h
The sum of speeds of boat and current is the downstream rate:
(440 km)/(5 h) = 88 km/h
The rate of the boat is half the sum of these:
(56 +88)/2 = 72 . . . km/h
The rate of the current is half their difference:
(88 -56)/2 = 16 . . . km/h
The rate of the boat is 72 km/h; the rate of the current is 16 km/h.
Answer:
The dolphin will be above the surface of the water for 2 seconds.
Step-by-step explanation:
Solving a quadratic equation:
Given a second order polynomial expressed by the following equation:
.
This polynomial has roots
such that
, given by the following formulas:



The height of the dolphin after t seconds is given by:

According to Micha's model, how long will the dolphin be above the surface of the water?
It stays above the surface of the water between the first and the second root. Initially, it is below water, when the first time for which
it crosses the surface upwards, and then the second time for which
it crosses the surface downwards.
We have to find these roots. So


Multiplying by -16




4 - 2 = 2
The dolphin will be above the surface of the water for 2 seconds.
Answer:
Step 1 :
Split the figure into 3 parts
part 1: triangle with base = 7 + 2 + 6 = 15in, height = 7in
part 2 : Rectangle with breadth = 3 + 6 + 2= 11in and length 8in
Part 3 :Rectangle with breadth 2in and length 9in
Step 2 :
find the area of each part
Area of part 1

Area of part 2

Area of part 3

Total area = 52.5 + 88 + 18 = 158.5 sqaure inches