Find each missing length to the nearest tenth

Suppose it takes 2 1/2 h to drive from your house to the lake at 48 mi/h. How long will your return trip take at 40 mi/h?

Y_Kistochka [10]

Answer

The distance from the house to the lake is (2.5 hr)*(48 mi/hr) = 120 miles. The rerurn trip would take (120 mi)/(40 mi/hr) = 3 hours. Distance equals rate times time, so the distance to the lake is 2 1/2 hours times 48 miles per hour.

I hope this helps

4 0

2 years ago

A golfball is hit from the ground with an initial velocity of 200 ft/sec. The horizontal distance that the golfball will travel,

algol13

Answer:

The golfball launched with an initial velocity of 200ft/s will travel the maximum possible distance which is 1250 ft when it is hit at an angle of $\pi/4$ .

Step-by-step explanation:

The formula from the maximum distance of a projectile with initial height h=0, is:

$d(\theta)=\frac{v_i^2sin(2\theta)}{g}$

Where $v_i$ is the initial velocity.

In the closed interval method, the first step is to find the values of the function in the critical points in the interval which is $[0, \pi/2]$ . The critical points of the function are those who make $d'(\theta)=0$ :

$d(\theta)=\frac{v_i^2\sin(2\theta)}{g}\\d'(\theta)=\frac{v_i^2\cos(2\theta)}{g}*(2)\\d'(\theta)=\frac{2v_i^2\cos(2\theta)}{g}$

$d'(\theta)=0\\\frac{2v_i^2\cos(2\theta)}{g}=0\\\cos(2\theta)=0\\2\theta=\pi/2,3\pi/2,5\pi/2,...\\\theta=\pi/4,3\pi/4,5\pi/4,...$

The critical value inside the interval is $\pi/4$ .

$d(\theta)=\frac{v_i^2sin(2\theta)}{g}\\d(\pi/4)=\frac{v_i^2sin(2(\pi/4))}{g}\\d(\pi/4)=\frac{v_i^2sin(\pi/2)}{g}\\d(\pi/4)=\frac{v_i^2(1)}{g}\\d(\pi/4)=\frac{(200)^2}{32}\\d(\pi/4)=\frac{40000}{32}\\d(\pi/4)=1250ft$

The second step is to find the values of the function at the endpoints of the interval:

$d(\theta)=\frac{v_i^2sin(2\theta)}{g}\\\theta=0\\d(0)=\frac{v_i^2sin(2(0))}{g}\\d(0)=\frac{v_i^2(0)}{g}=0ft\\\theta=\pi/2\\d(\pi/2)=\frac{v_i^2sin(2(\pi/2))}{g}\\d(\pi/2)=\frac{v_i^2sin(\pi)}{g}\\d(\pi/2)=\frac{v_i^2(0)}{g}=0ft$

The biggest value of f is gived by $\pi/4$ , therefore $\pi/4$ is the absolute maximum.

In the context of the problem, the golfball launched with an initial velocity of 200ft/s will travel the maximum possible distance which is 1250 ft when it is hit at an angle of $\pi/4$ .

4 0

3 years ago

One pound of apples costs $3.25 . Five pounds of apples cost $16.25

UNO [17]

Answer:

that is correct

Explanation:

3.25*5=16.25

4 0

2 years ago

Reuben bought 5CDS that were each the same priceIncluding sales tax, he paid a total of \$81.50. Each CD had a tax of $0.60. wha

Liula [17]

Answer:

The price of each CD before tax is $15.70

Step-by-step explanation:

Given that:

Number of CDs bought by Reuben = 5

Cost of five CDs = $81.50

Sales tax on each CD = $0.60

Sales tax on 5 CDs = 0.60*5 = $3.00

Price of CDs without tax = 81.50 - 3.00 = $78.50

Price of each CD = $\frac{Cost\ of\ CDs}{No.\ of\ CDs}$

Price of each CD = $\frac{78.50}{5}$

Price of each CD = $15.70

Hence,

The price of each CD before sales tax is $15.70

7 0

2 years ago

In the below figure what is the value of ∠QPR, in degrees, if ∠SPQ is a straight line? The measure of a straight angle is 180 de

inysia [295]

Answer:

180

Step-by-step explanation:

spr is one line and qp is another in a perpendicular position

6 0

3 years ago