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3 years ago

Define the Earth's atmosphere

1 answer:

7 0

The blanket of gas on the surface of a planet or satellite. Note: The atmosphere of the Earth is roughly eighty percent nitrogen and twenty percent oxygen, with traces of other gases. (See ionosphere, stratosphere, and troposphere.)

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Which of the following is an electric potential?

Dennis_Churaev [7]

Answer:

D. 2.5 V

Explanation:

Electric potential of a point in space is a scalar magnitude that allows a measurement of the electric field at that point to be obtained through the electrostatic potential energy that a electric charge would acquire if it is placed at that point.

8 0

3 years ago

Read 2 more answers

Three balls with the same radius 18 cm are in water. Ball 1 floats, with half of it exposed above the water level. Ball 2, with

Kay [80]

Answer:

(a)

4) The magnitude of buoyancy force is equal to that of ball's weight

(b) The magnitude of buoyancy force is larger than that of ball's weight. The tension on second ball is 158 newtons

Explanation:

Newton's third law of motion states that forces always occurs in pairs. For every reaction there is an equal an opposite reaction. For Ball 1 the magnitude of buoyancy force is equal to that of ball's weight. Buoyancy force works against the gravity. Ball 2 and ball 3 have same buoyancy force. The buoyancy force for ball 2 and ball 3 is larger than that of ball's weight.

Tension = Wb - fb

Tension for Ball 2 = 1000 - 842 = 158 newtons

Tension for Ball 3 = 1000 - 1218 = -218 newtons

3 0

3 years ago

If you hold your arm outstretched with palm upward, the force to keep your arm from falling comes from your deltoid muscle. assu

Maurinko [17]

Your question seems to be incorrect. Please check below:

What force must the deltoid muscle provide to keep the arm in this position? By what factor does this force exceed the weight of the arm?If you hold your arm outstretched with palm upward, as in (Figure 1) , the force to keep your arm from falling comes from your deltoid muscle. Assume that the arm has mass 4 kg and the distances and angles shown in (Figure 1) .

F=?
F/w= ?

The answer is 339 N

4 0

3 years ago

Electronic flash unit cameras contain a capacitor for storing the energy used to produce the flash. In one such unit the flash l

Stolb23 [73]

Answer:

(A) 421 J energy stored in the capacitor for one flash.

(B) The value of capacitance is 0.0537 F

Explanation:

Given :

(A)

Time $t = \frac{1}{675}$

Average power $P = 2.7 \times 10^{5}$ W

From power equation,

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

So energy in one light is given by,

$E = Pt$

$E = 2.7 \times 10^{5} \times \frac{1}{675} = 400$ J

Since efficiency is 95 % so we can write, energy stored in one flash,

$E_{tot} = \frac{400}{0.95} = 421$ J

(B)

From the formula of energy stored in capacitor,

$E = \frac{1}{2}C V^{2}$

Where $E = E_{tot}$ and $V = 125$ V

$C = \frac{2E}{V^{2} }$

$C = \frac{2 \times 421}{15625}$

$C = 0.0537 F$

8 0

3 years ago

At the instant the traffic light turns green, an automobile starts with a constant acceleration a of 2.5 m/s2. At the same insta

Licemer1 [7]

Answer:

6.96 s

Explanation:

Given:

u = initial speed of the automobile = 0 m/s

a = constant acceleration of the automobile = $2.5\ m/s^2$
v = constant speed of the truck = 8.7 m/s

Assume:

t = time instant at which the automobile overtakes the truck.

At the moment the automobile and the truck both meat each other the distance travel by both vehicles must be the same.

$\therefore \textrm{Distance traveled by the automobile }=\textrm{Distance traveled by the truck}\\\Rightarrow ut+\dfrac{1}{2}at^2=vt\\\Rightarrow (0)t+\dfrac{1}{2}\times 2.5\times t^2=8.7t\\\Rightarrow 1.25t^2=8.7t\\\Rightarrow 1.25t^2-8.7t=0\\\Rightarrow t(1.25t-8.7)=0\\\Rightarrow t = 0\,\,\,or\,\,\, t = \dfrac{8.7}{1.25}\\\Rightarrow t = 0\,\,\,or\,\,\, t = 6.96\\$

Since t = 0 s is the initial condition. So, they both meet again at t = 6.96 s such that the automobile overtakes the truck.

6 0

3 years ago