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2 years ago

20. Q: How long will it take for an apple falling from a 29.4m-tall tree to hit the ground?

Physics

1 answer:

saul85 [17]2 years ago

7 0

Answer:

2.45s

Explanation:

is explanation needed too?

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Because of its center-surround organization, a neuron that has its entire receptive field exposed to bright light will:

Tom [10]

Answer:

b. maintain the same rate of firing as if there was no light presented.

Explanation:

The neuron will maintain the same rate of firing as if there was no light presented.

Receptive filed of neuron is place on its sensory surface generally on the back of eye that an stimulus must reach to activate the neuron. The bright light cannot change the rate of firing of the neuron.

5 0

4 years ago

A car accelerates uniformly from 5m/s to 15m/s taking 7.5 seconds. How far did it travel during this period

vodomira [7]

The required answer is 66.925 m which is the distance travelled by the car.

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3 years ago

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A spacecraft is fueled using hydrazine (N2H4; molecular weight of 32 grams per mole [g/mol]) and carries 1640 kilograms [kg] of

Sauron [17]

Answer:

The value is $t = 689.029 \ hours$

Explanation:

From the question we are told that

The molar mass of hydrazine is $Z = 32 g/mol = \frac{32}{1000} = 0.032 \ kg/mol$

The initial temperature is $T_i = -186 ^o F = (-186-32) *\frac{5}{9} +273.15 = 152\ K$

The final temperature is $T_f = 78 ^o F = (78-32) *\frac{5}{9} +273.15 = 298.7 \ K$

The specific heat capacity is $c_h = 0.099 [kJ/(mol K)] = 0.099 *10^3 J/(mol/K)$

The power available is $P = 300 \ W$

The mass of the fuel is $m = 1640 \ kg$

Generally the number of moles of hydrazine present is

$n = \frac{m}{Z}$

=> $n = \frac{1640}{= 0.032}$

=> $n = 51250 \ mol$

Generally the quantity of heat energy needed is mathematically represented as

$Q = n * c_h * (T_f -T_i)$

=> $Q = 51250 * 0.099 *10^3 * (298.7 - 152)$

=> $Q = 7.441516913 * 10^{8} \ J$

Generally the time taken is mathematically represented as

$t = \frac{Q}{P}$

=> $t = \frac{7.441516913 * 10^{8} }{300}$

=> t = 2480505.6377 s

Converting to hours

$t = \frac{2480505.6377}{3600}$

=> $t = 689.029 \ hours$

6 0

3 years ago

A point on a wheel of radius 40 cm that is rotating at a constant 5.0 revolutions per second is located 0.20 m from the axis of

Margarita [4]

Answer:

$197.2 m/s^2$

Explanation:

The centripetal acceleration of a point moving by circular motion is given by:

$a=\omega^2 r$

where

$\omega$ is the angular velocity

r is the distance from the axis of rotation

The point on the wheel makes 5.0 revolutions per second, so the frequency is

$f=\frac{5}{1}=5 Hz$

and the angular velocity is

$\omega=2\pi f = 2\pi (5)=31.4 rad/s$

While the distance of the point from the axis of rotation is

$r=0.20 m$

Substituting, we find the acceleration:

$a=(31.4)^2(0.20)=197.2 m/s^2$

5 0

3 years ago

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Why is carrying for the earth necessary? explain

monitta

Answer: We will survive

Explanation: Caring for the earth is something that we need to do to live or survive on earth because if we don't we may not survive.

Hope this helps! :)

6 0

3 years ago

Read 2 more answers