Ask question

Ask question

All categories

4 years ago

9

During a tornado in 2008 the Peachtree Plaza Westin Hotel in downtown Atlanta suffered damage. Suppose a piece of glass dropped

near the top of the hotel falls 215 meters. How long would it take the piece of glass to hit the ground?

1 answer:

Darina [25.2K]4 years ago

3 0

Answer:

Time = t = 6.62 s

Explanation:

Given data:

Height = h = 215 m

Initial velocity = $v_{i}$ = 0 m/s

gravitational acceleration = g = 9.8 m/s²

Time = t = ?

According to second equation of motion

$h = v_{i}t + \frac{1}{2}gt^{2}$

As initial velocity is zero, So the first term of right hand side of above equation equal to zero.

$h = \frac{1}{2}gt^{2}$

t² = $\frac{2h}{g}$

t = $\sqrt{\frac{2h}{g} }$

t = $\sqrt{\frac{(2)(215) }{9.8} }$

t = 6.62 s

You might be interested in

Say I have a series circuit with 20v and four 65 ohm resistors, what is the current in each resistor?

Komok [63]

Data:

$E = 20 V$
$R_{1} = 65\Omega$
$R_{2} = 65\Omega$
$R_{3} = 65\Omega$
$R_{4} = 65\Omega$

<span>Now that we have all the values we need properly identified, simply calculate the equivalent total resistance of the circuit and the intensity of the total electric current using the Ohm's Law:

</span> $R_{T} = R_{1} + R_{2} + R_{3} + R_{4}$
$R_{T} = 65 + 65 + 65+ 65$
$R_{T} = 260\Omega$

<span>Like this:
</span>
$I_{T} = \frac{E}{ R_{T} }$

$I_{T} = \frac{20}{ 260 }$
$I_{T} = 0,076923076...$

$\boxed{\boxed{I_{T} \approx 0,07A}}$
Answer:
<span>The intensity of the total electric current
</span> $\boxed{\boxed{I_{T} \approx 0,07A}}$

P.S:. Since the association is in series, the current of 0.07A is the same for all resistors.

4 0

3 years ago

A 0.80 kg object tied to the end of a 2.0 m string swings as a pendulum. At the lowest point of its swing, the object has a kine

devlian [24]

Answer:

3.32 m/s

Explanation:

From the law of conservation of energy, the sum of mechanical and kinetic energy should be equal to the 10 J given. Potential energy is given by mgh where m is mass, g is acceleration due to gravity and h is the height. For this case, $h= l(1-cos\theta)$ and l is string length, given as 2 m, \theta is given as 50 degrees. Kinetic energy is given by $0.5mv^{2}$ and it is this velocity that is unknown.

$10J=0.5\times 0.8kg\times v^{2}+ 0.8kg\times 9.81\times 2m(1-cos 50^{\circ})\\v\approx 3.32 m/s$

6 0

4 years ago

Currents in dc transmission lines can be 100 A or higher. Some people are concerned that the electromagnetic fields from such li

lozanna [386]

Answer: 4.50*10^-6T (0.00000450071T)

Explanation: A current carrying conductor has been knowing to generate a specific amount of magnetic field.

This is given by the Bio-savart law (mathematical).

The Bio-savart law is a mathematical equation that gives the value of strength of the magnetic field created by a current carrying conductor.

B=(Uo* I) /2πr

Where

B= strength of magnetic field

Uo = magnetic permeability in free space = 1.257 *10^-6

r = distance between current carrying conductor and any reference point.

By doing the neccesary algebra, we have

B=(1.257 *10^-6 * 180)/ (2 * 3.142 * 8)

B= 2.2626 *10^-4 / 50.2857

B=4.5 * 10^-6T (0.00000450071T)

6 0

3 years ago

In some areas, farmers have installed windmills to generate electricity to run the farm.

Aleks [24]

Answer:

Number 3

Explanation:

Unlike other numbers, this states that wind is "renewable". The choice 2 sounds a bit selfish, or not worded properly, I believe choice 3 is the answer. However, you are the judge of choosing to believe this or not.

Good luck!

8 0

2 years ago

Which type of reaction does this chemical equation represent? 2Na + MgCl2 - 2NaCl + Mg

Airida [17]

Answer: Single replacement

Explanation: A P E X

5 0

3 years ago

Read 2 more answers