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4 years ago

An student dropped their book from the top of a canyon into a river 40 meters below.

Physics

1 answer:

kotykmax [81]4 years ago

7 0

Use this formula for an object starting from rest and accelerating:

Distance = (1/2) (acceleration) (time)²

In this problem, the distance is 40 meters, and acceleration is gravity.

So . . .

40 m = (1/2) (9.8 m/s²) (time)²

Divide each side by (4.9 m/s²) :

time² = (40 m) / (4.9 m/s²)

time² = 8.16 sec²

Take the square root of each side :

√(time²) = √(8.16 sec²)

time = 2.86 seconds

Round it to 2.9 sec <em>(choice B)</em>

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Can any kind soul help me

Wittaler [7]

Answer:

2917.4 m/s

Explanation:

From the question given above, the following data were:

Gravitational acceleration of the Moon (g) = 0.25 times the gravitational acceleration of the earth

Radius (r) of the Moon = 1737 Km

Escape velocity (v) =?

Next, we shall determine the gravitational acceleration of the Moon. This can be obtained as follow:

Gravitational acceleration of the earth = 9.8 m/s²

Gravitational acceleration of the Moon (g) = 0.25 times the gravitational acceleration of the earth

= 0.25 × 9.8 = 2.45 m/s²

Next, we shall convert 1737 Km to metres (m). This can be obtained as follow:

1 Km = 1000 m

Therefore,

1737 Km = 1737 Km × 1000 m / 1 Km

1737 Km = 1737000 m

Thus, 1737 Km is equivalent to 1737000 m

Finally, we shall determine the escape velocity of the rocket as shown below:

Gravitational acceleration of the Moon (g) = 2.45 m/s²

Radius (r) of the moon = 1737000 m

Escape velocity (v) =?

v = √2gr

v = √(2 × 2.45 × 1737000)

v = √8511300

v = 2917.4 m/s

Thus, the escape velocity is 2917.4 m/s

4 0

3 years ago

One advantage of light microscopy over transmission electron microscopy is that One advantage of light microscopy over transmiss

il63 [147K]

Answer:

d. light microscopy allows one to view dynamic processes in living cells.

Explanation:

One advantage of light microscopy over transmission electron microscopy is that light microscopy allows one to view dynamic processes in living cells.

Electron microscope differ from the light microscope because electron micoscope produce the image of the specimen using electron beam and not light. Electron microscopy samples must be kept in vacuum, this means live cells can not be imaged.

4 0

4 years ago

What does a producer need to make its own food

azamat

Answer:

A producer needs the sun to make its own food, because producers use photosynthesis. In photosynthesis you use the sun to turn the air people breathe out and water into glucose and oxygen.

Explanation:

Hope this helps ^-^

7 0

3 years ago

In an LC circuit at one time the charge stored by the capacitor is 10 mC and the current is 3.0 A. If the frequency of the circu

Ronch [10]

Answer:

$i_2=3.61\ A$

Explanation:

<u>LC Circuit</u>

It's a special circuit made of three basic elements: The AC source, a capacitor, and an inductor. The charge, current, and voltage are oscillating when there is an interaction between the electric and magnetic fields of the elements. The following variables will be used for the formulas:

$q, q_1, q_2$ = charge of the capacitor in any time $t, t_1, t_2$

$q_o$ = initial charge of the capacitor

$\omega$ =angular frequency of the circuit

$i, i_1, i_2$ = current through the circuit in any time $t, t_1, t_2$

The charge in an LC circuit is given by

$q(t) = q_0 \, cos (\omega t )$

The current is the derivative of the charge

$\displaystyle i(t) = \frac{dq(t)}{dt} = - \omega q_0 \, sin(\omega t).$

We are given

$q_1=10\ mc=0.01\ c, i_1=3\ A,\ q_2=6\ mc=0.006\ c\ ,\ f=\frac{1000}{4\pi}$

It means that

$q(t_1) = q_0 \, cos (\omega t_1 )=q_1\ .......[eq 1]$

$i(t_1) = - \omega q_0 \, sin(\omega t_1)=i_1.........[eq 2]$

From eq 1:

$\displaystyle cos (\omega t_1 )=\frac{q_1}{q_0}$

From eq 2:

$\displaystyle sin(\omega t_1)=-\frac{i_1}{\omega q_0}$

Squaring and adding the last two equations, and knowing that

$sin^2x+cos^2x=1$

$\displaystyle \left ( \frac{q_1}{q_0} \right )^2+\left ( \frac{i_1}{\omega q_0} \right )^2=1$

Operating

$\displaystyle \omega^2q_1^2+i_1^2=\omega^2q_o^2$

Solving for $q_o$

$\displaystyle q_o=\frac{\sqrt{\omega^2q_1^2+i_1^2}}{\omega}$

Now we know the value of $q_0$ , we repeat the procedure of eq 1 and eq 2, but now at the second time $t_2$ , and solve for $i_2$

$\displaystyle \omega^2q_2^2+i_2^2=\omega^2q_o^2$

Solving for $i_2$

$\displaystyle i_2=w\sqrt{q_o^2-q_2^2}$

Now we replace the given values. We'll assume that the placeholder is a pi for the frequency, i.e.

$\displaystyle f=\frac{1}{4\pi}\ KHz$

$w=2\pi f=500\ rad/s$

$\displaystyle q_o=\frac{\sqrt{(500)^2(0.01)^2+3^2}}{500}$

$q_0=0.01166\ c$

Finally

$\displaystyle i_2=500\sqrt{0.01166^2-.006^2}$

$i_2=5\ A$

3 0

3 years ago

What are the potential hazards associated with using soil

allochka39001 [22]

Soil contains vermiculite, a natural mineral.Even though Vermiculite holds water, it can be dangerous for the human body. It's filled with naturally occurring asbestos, and when asbestos is breathed in, it can risk our respiratory system. In addition, soil has a potentially serious disease causes from bacteria called Legionnaires' Disease. It's very dangerous, especially for the people with a weak immune system.
Hope this helps.
(Please mark this brainliest, I would really appreciate it) Thanks!

8 0

3 years ago