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3 years ago

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When the comet passes close to the sun, it has a visible tail. Typically, the comet is only visible for a matter of days while i

t may be invisible for years. Why does the comet spend so little time close to the sun?

1 answer:

Nataly [62]3 years ago

7 0

Answer:

The comet is locked in the Sun's gravity. as it falls deeper in the gravity we'll, its velocity increases. As is travels closer to the Sun, it is trying to break away, but cannot. This transforms into a sideways movement that produces a tight turn. It races further out of the gravity well, and sheds velocity.

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Now in "real life," this automobile is cruising at 20.5 m/s (equal to 73.8 km/hr) when it is about to hit a pedestrian stuck in

algol13

Answer:

He needs 1.53 seconds to stop the car.

Explanation:

Let the mass of the car is 1500 kg

Speed of the car, v = 20.5 m/s

He will not push the car with a force greater than, $F=2\times 10^4\ N$

The impulse delivered to the object is given by the change in momentum as :

$F\times t=mv\\\\t=\dfrac{mv}{F}\\\\t=\dfrac{1500\times 20.5}{2\times 10^4}\\\\t=1.53\ s$

So, he needs 1.53 seconds to stop the car. Hence, this is the required solution.

5 0

3 years ago

Assume the price of gasoline doubles tonight and remains at that price the next two years. The price elasticity of demand for ga

Serggg [28]

Answer:

more inelastic

Explanation:

Assume the price of gasoline doubles tonight and remains at that price for the next two years. The price elasticity of demand for gasoline measured tomorrow will be <u>more inelastic</u> when compared with the price elasticity of demand for gasoline measured two years from now.

Inelastic refers to the static quantity of a good or service when its price changes.

5 0

3 years ago

The block in the drawing has dimensions L0×2L0×3L0,where L0 =0.5 m. The block has a thermal conductivity of 200 J/(s·m·C˚). In d

Dennis_Churaev [7]

Answer:

$Q_p=18000\ J$

$Q_o=8000\ J$

$Q_g=72000\ J$

Explanation:

Given:

Length of block, $l=3L_o=3\times 0.5=1.5\ m$

Breadth of block, $b=L_o=0.5\ m$

height of block, $h=2L_o=2\times 0.5=1\ m$

Thermal conductivity of the block, $k=200\ W.m.^{\circ}C$

Temperature on the hotter side, $T_H=37^{\circ}C$

temperature on the cooler side, $T_L=7^{\circ}C$

time for which the heat flows, $t=4\ s$

<u>REFER THE ATTACHED IMAGE FOR THE REFERENCE</u>

<em>The rate of heat flow using </em><em>Fourier's law</em><em> of conduction is given as:</em>

$\frac{Q}{t}=k.A.\frac{dT}{dx}$

<u>Now the amount heat flow perpendicular to the pink surface:</u>

$\frac{Q_p}{4}=200\times (0.5\times 1.5).\frac{30}{1}$

$Q_p=18000\ J$

<u>Now the amount heat flow perpendicular to the orange surface:</u>

$\frac{Q_o}{4}=200\times (0.5\times 1).\frac{30}{1.5}$

$Q_o=8000\ J$

<u>Now the amount heat flow perpendicular to the green surface:</u>

$\frac{Q_g}{4}=200\times (1.5\times 1).\frac{30}{0.5}$

$Q_g=72000\ J$

6 0

3 years ago

A brick is dropped (zero initial speed) from the roof of a building. The brick strikes the ground in 1.90 s. You may ignore air

Gekata [30.6K]

Answer: Height of building = 17.69m, velocity of brick = 18.6m/s

Explanation: From the question, the body has a zero initial speed, thus initial velocity (u) all through the motion is zero.

By ignoring air resistance makes it a free fall motion thus making it to accelerate constantly with a value of $a = 9.8m/s^{2}$ .

Time taken to fall = 1.90s

a)

thus the height of the building is calculated using the formulae below

$H = ut + \frac{1}{2} gt^{2}$

but u = 0 , hence

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

$H = \frac{1}{2} *9.8* 1.9^{2} \\\\H = 17.69m$

b)

to get the value of velocity (v) as the brick hits the ground, we use the formulae below

$v^{2} = u^{2} + 2aH$

but u= 0, hence

$v^{2} = 2gH\\$

$v^{2} = 2 * 9.8 * 17.69\\v = \sqrt{2 *9.8* 17.69} \\v = 18.62m/s$

find the attachment in this answer for the accleration- time graph, velocity- time graph and distance time graph

8 0

4 years ago

14. Which of the following is not an example of work being done?

Natali5045456 [20]

Answer:

B. holding a coffee mug

Explanation:

Something must move a distance for work to be done.

7 0

3 years ago