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3 years ago

A 10 kg object is travelling at 2.0 m/s. After 30 seconds the object's speed becomes 3.0

Physics

2 answers:

belka [17]3 years ago

7 0

I think this might be the answer, if it is I’ll be very surprised =/

mylen [45]3 years ago

3 0

Answer:7350 joules

Explanation:

Mass(m)=10kg

Initial velocity(u)=2m/s

Final velocity(v)=3m/s

Time(t)=30s

Acceleration horizontally=a

Acceleration due to gravity(g)=9.8m/s^2

d=(u+v)/2 x t

d=(2+3)/2 x30

d=5/2 x 30

d=(5x30)/2

d=150/2

d=75

Force=mass x acceleration due to gravity

Force=10x9.8

Force=98N

Work=force x distance

Work=98 x 75

Work=7350J

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Ngan has a weight of 314.5 N on Mars and a weight 833.0 N on Earth. What is Ngan's mass on Earth?

mr_godi [17]

Ngan's mass on earth is 85kg.

Ngan has a weight on Mars = 14.5 N

Ngan’s weight on Earth = 833.0 N

Ngan’s mass on Earth = ?

Fg,earth = mg(earth)

M = Fg,earth / g(earth)

M = 833.0 N / 9.8 m/s2

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3 years ago

Read 2 more answers

When a positive charge moves in the direction of the electric field, what happens to the electrical potential energy associated

VladimirAG [237]

Answer:

B it decreases

Explanation:

the movement of a positive test charge in the direction of an electric field would be like a mass falling downward within Earth's gravitational field. Both movements would be like going with nature and would occur without the need of work by an external force. This motion would result in the loss of potential energy

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3 years ago

The Hubble Space Telescope in orbit above the Earth has a 2.4 m circular aperture. The telescope has equipment for detecting ult

strojnjashka [21]

Answer:

Option d

The minimum angular separation between two objects that the Hubble Space Telescope can resolve is $4.8x10^{-8}rad$ .

Explanation:

The resulting image in a telescope that will be gotten from an object is a diffraction pattern instead of a perfect point (point spread function (PSF)).

That diffraction pattern is gotten because the light encounters different obstacles on its path inside the telescope (interacts with the walls and edges of the instrument).

The diffraction pattern is composed by a central disk, called Airy disk, and diffraction rings.

The angular resolution is defined as the minimal separation at which two sources can be resolved one for another, or in other words, when the distance between the two diffraction pattern maxima is greater than the radius of the Airy disk.

The angular resolution can be determined in analytical way by means of the Rayleigh criterion.

$\theta = 1.22\frac{\lambda}{D}$ (1)

Where $\lambda$ is the wavelength and D is the diameter of the telescope.

Notice that it is necessary to express the wavelength in the same units than the diameter.

$\lambda = 95nm \cdot \frac{1x10^{-9}m}{1nm}$ ⇒ $9.5x10^{-8}m$

Finally, equation 1 can be used.

$\theta = 1.22(\frac{9.5x10^{-8}m}{2.4m})$

$\theta = 4.8x10^{-8}rad$

Hence, the minimum angular separation between two objects that the Hubble Space Telescope can resolve is $4.8x10^{-8}rad$ .

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3 years ago

When a rocket is 4 kilometers high, it is moving vertically upward at a speed of 400 kilometers per hour. At that instant, how f

Y_Kistochka [10]

Answer:

The angle of elevation of the rocket is increasing at a rate of 48.780º per second.

Explanation:

Geometrically speaking, the distance between the rocket and the observer ( $r$ ), measured in kilometers, can be represented by a right triangle:

$r = \sqrt{x^{2}+y^{2}}$ (1)

Where:

$x$ - Horizontal distance between the rocket and the observer, measured in kilometers.

$y$ - Vertical distance between the rocket and the observer, measured in kilometers.

The angle of elevation of the rocket ( $\theta$ ), measured in sexagesimal degrees, is defined by the following trigonometric relation:

$\tan \theta = \frac{y}{x}$ (2)

If we know that $x = 5\,km$ , then the expression is:

$\tan \theta = \frac{y}{5}$

And the rate of change of this angle is determined by derivatives:

$\sec^{2}\theta \cdot \dot \theta = \frac{1}{5}\cdot \dot y$

$\frac{\dot \theta}{\cos^{2}\theta} = \frac{\dot y}{5}$

$\frac{\dot \theta\cdot (25+y^{2})}{25} = \frac{\dot y}{5}$

$\dot \theta = \frac{5\cdot \dot y}{25+y^{2}}$

Where:

$\dot \theta$ - Rate of change of the angle of elevation, measured in sexagesimal degrees.

$\dot y$ - Vertical speed of the rocket, measured in kilometers per hour.

If we know that $y = 4\,km$ and $\dot y = 400\,\frac{km}{h}$ , then the rate of change of the angle of elevation is:

$\dot \theta = 48.780\,\frac{\circ}{s}$

The angle of elevation of the rocket is increasing at a rate of 48.780º per second.

3 0

3 years ago

The friction that prevents an object from moving when a force is applied is ________ friction.

uranmaximum [27]

Static friction is what you are looking for.
Kinetic friction is the force exerted on an already moving object, slowing it down.

3 0

3 years ago