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Assoli18 [71]
4 years ago
9

What was the average speed in km/h of:

Mathematics
1 answer:
nirvana33 [79]4 years ago
6 0

Answer:

The average speed of the boat is 20 km/hr.

Step-by-step explanation:

Given : A boat that moves 15.0 km across a lake in 45 min.

To find : What was the average speed in km/h ?

Solution :

The distance a boat covered is 15 km.

The time taken by boat to cross a lake is 45 minutes.

Convert minute into hour,

1 hour = 60 minute

1 minute = \frac{1}{60} hour

45 minute = \frac{45}{60} hour

45 minute = 0.75 hour

The speed of the boat is given by,

\text{Speed}=\frac{\text{Distance}}{\text{Time}}

\text{Speed}=\frac{15}{0.75}

\text{Speed}=20

The average speed of the boat is 20 km/hr.

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Determining Components of an Exponential Function A doctor estimates that a particular patient is losing bone density at a rate
Ipatiy [6.2K]

Answer:

f(x) = 1500(0.97)ˣ

Step-by-step explanation:

Given that:

f(x) = abˣ

a is the initial bone density, that is the bone density at 0 years, x is the number of years and b is any real value. For an exponential growth, b > 1 while for an exponential decay, b < 1.

Since the bone has a current density of 1,500 kg/m³, hence a = 1500.

The density is lost at a rate of 3% annually, therefore b = 100% - 3% = 97% = 0.97.

Therefore substituting the values of a and b into the function gives:

f(x) = 1500(0.97)ˣ

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Step-by-step explanation:

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