What’s (2.5,6) dilated by a scale factor of 2?

1. (a). A police car, approaching right-angled intersection from the north, is chasing a speedmg

tamaranim1 [39]

Answer:

The SUV is running at 70 km/h

Step-by-step explanation:

Speed As Rate Of Change

The speed can be understood as the rate of change of the distance in time. When the distance increases with time, the speed is positive and vice-versa. The instantaneous rate of change of the distance allows us to find the speed as a function of time.

This is the situation. A police car is 0.6 Km above the intersection and is approaching it at 60 km/h. Since the distance is decreasing, this speed is negative. On the other side, the SUV is 0.8 km east of intersection running from the police. The distance is increasing, so the speed should be positive. The distance traveled by the police car (y) and the distance traveled by the SUV (x) form a right triangle whose hypotenuse is the distance between them (d). We have:

$d=\sqrt{x^2+y^2}$

To find the instant speeds, we need to compute the derivative of d respect to the time (t). Since d,x, and y depend on time, we apply the chain rule as follows:

$\displaystyle d\ '=\frac{x.x'+y.y'}{\sqrt{x^2+y^2}}$

Where x' is the speed of the SUV and y' is the speed of the police car (y'=-60 km/h)

We'll compute :

$d=\sqrt{(0.8)^2+(0.6)^2}=\sqrt{0.64+0.36}$

$d=1\ km$

We know d'=20 km/h, so we can solve for x' and find the speed of the SUV

$\displaystyle \frac{x.x'+y.y'}{\sqrt{x^2+y^2}}=20$

Thus we have

$x.x'+y.y'=20$

Solving for x'

$\displaystyle x'=\frac{20-y.y'}{x}$

Since y'=-60

$\displaystyle x'=\frac{20+0.6(60)}{0.8}$

$x'=70\ km/h$

The SUV is running at 70 km/h

7 0

3 years ago

Help me to simplify; log_{5} 12.5+log_{5}10

liq [111]

Answer:

15.726

Step-by-step explanation:

log 5=0.698×12.5

=8.737

=0.698×10

=6.989

=8.737+6.989

=15.726

8 0

3 years ago

Juan works at bob’s appliance store . he earns $400 per week he also receives a commission of $50 for each appliance he sels

sweet-ann [11.9K]

Answer:

400×W+50×A=?

Step-by-step explanation:

since it's 400 a week then you need to take into account the weeks worked. Then since it's 50 per an appliance you need to multiply by the number sold.

5 0

3 years ago

The average temperature in Hawaii is about 23°C. Which of the following best describes 23°C? A. 9°C above freezing B. 23°C above

zzz [600]

The answer is B) 23C above freezing.
0C is freezing temperature for water, that equals 32F

7 0

3 years ago

There are 14 juniors and 16 seniors in a chess club. a) From the 30 members, how many ways are there to arrange 5 members of the

Dmitrij [34]

Answer:

a) 17,100,720

b) 4,717,440

c) 10,920

d) 2821

Step-by-step explanation:

14 juniors and 16 seniors = 30 people

a) From the 30 members, how many ways are there to arrange 5 members of the club in a line?

As it is a ordered arrangement

30.29.28.27.26 = 17,100,720

b) How many ways are there to arrange 5 members of the club in a line if there must be a senior at the beginning of the line and at the end of the line?

16.28.27.26.15 = 4,717,440

c) If the club sends 2 juniors and 2 seniors to the tournament, how many possible groupings are there?

Not ordered arrangement. And means that we need to multiply the results.

C₁₄,₂ * C₁₆,₂

C₁₄,₂ = 14.13.12! = 14.13 = 91

12! 2! 2

C₁₆,₂ = 16.15.14! = 16.15 = 120

14! 2! 2

C₁₄,₂ * C₁₆,₂ = 91.120 = 10,920

d) If the club sends either 4 juniors or 4 seniors, how many possible groupings are there?

Or means that we need to sum the results.

C₁₄,₄ + C₁₆,₄

C₁₄,₄ = 14.13.12.11.10! = 14.13.12.11 = 1001

10! 4! 4.3.2.1

C₁₆,₄ = 16.15.14.13.12! = 16.15.14.13 = 1820

12! 4! 4.3.2.1

C₁₄,₄ + C₁₆,₄ = 1001 + 1820 = 2821

7 0

3 years ago