Ask question

Ask question

All categories

3 years ago

10

You are in a hot air balloon, 650 m above the flat Texas plains. The Earth's radius is about 6400 km.You look out toward the hor

izon. How far out can you see−that is, how far is your horizon?

1 answer:

Molodets [167]3 years ago

4 0

Answer:

91 km

Explanation:

Draw a picture. The line of sight to the horizon forms a tangent line with the curvature of the Earth. The radius line to that point forms a right angle with the tangent line. So we can use Pythagorean theorem to find the distance.

c² = a² + b²

(6400 km + 0.650 km)² = (6400 km)² + d²

d ≈ 91 km

You might be interested in

A car weighing 12,000 N is parked on a 36° slope. The car starts to roll down the hill. What is the acceleration of the car?

Delicious77 [7]

Answer: 5.8 m/s squared

Explanation: just got that question lol

4 0

3 years ago

A spring has a spring constant of 20 N/m. How much potential energy is stored in the spring as it stretched 0.20 m

makkiz [27]

The elastic potential energy (Ep) is given by $Ep = \frac{1}{2}*k*x^2$

Data:
Ep = ? (Joule)
k = 20 N/m
x (displacement) = 0.20 m

Solving:
$Ep = \frac{1}{2}*k*x^2$
$Ep = \frac{1}{2}*20*0.20^2$
$Ep = \frac{20*0.04}{2}$
$Ep = \frac{0.8}{2}$
$\boxed{\boxed{Ep = 0.4\:J}}\end{array}}\qquad\quad\checkmark$

7 0

3 years ago

A has the magnitude 14.4 m and is angled 51.6° counterclockwise from the positive direction of the x axis of an xy coordinate sy

Ad libitum [116K]

Answer:

Ã in unit vector notation = 12.26485i + 7.54539j

B in unit vector notation = 16.3516i + 3.11529j

Explanation:

The detailed steps and calculation is shown in the attachment.

7 0

3 years ago

According to one set of measurements, the tensile strength of hair is 196 MPa , which produces a maximum strain of 0.380 in the

slega [8]

Answer:

(a). The magnitude of the force is 0.38416 N.

(b). The original length is 0.0869 m.

Explanation:

Given that,

Tensile strength = 196 MPa

Maximum strain = 0.380

Diameter = 50.0 μm

Length = 12.0 cm

We need to calculate the area

Using formula of area

$A=\dfrac{\pi}{4}\times d^2$

Put the value into the formula

$A=\dfrac{\pi}{4}\times(50.0\times10^{-6})^2$

$A=1.96\times10^{-9}\ m^2$

We need to calculate the magnitude of the force

Using formula of force

$F=\sigma A$

Put the value into the formula

$F=196\times10^{6}\times1.96\times10^{-9}$

$F=0.38416\ N$

(b). If the length of a strand of the hair is 12.0 cm at its breaking point

We need to calculate the unstressed length

Using formula of strain

$strain=\dfrac{\Delta l}{l_{0}}$

$\Delta l=strain\times l_{0}$

Put the value into the formula

$\Delta l=0.380\times l_{0}$

Length after expansion is 12 cm

We need to calculate the original length

Using formula of length

$l=l_{0}+\Delta l$

Put the value into the formula

$I=l_{0}+0.380\times l_{0}$

$l=1.38l_{0}$

$l_{0}=\dfrac{l}{1.38}$

$l_{0}=\dfrac{12\times10^{-2}}{1.38}$

$l_{0}=0.0869\ m$

Hence, (a). The magnitude of the force is 0.38416 N.

(b). The original length is 0.0869 m.

4 0

4 years ago

Which hand is negatively charged?<br> ОА<br> ОВ.<br> Ос.<br> OD

Strike441 [17]

Answer is OB
Answer is OB
Answer is OB

8 0

3 years ago