All categories

3 years ago

What role did gravity play in the formation of the planets?

2 answers:

6 0

Gravitational forces brought together several moon-sized bodies, called planetesimals, to form larger bodies that became planets.

joja [24]3 years ago

3 0

Your answer would be D.
If an object has mass, it has gravity, and the more mass it has, the stronger its gravity. During the formation of planets, essentially, various matter and elements pulled and fused together (because of the gravity), forming planetesimals.

You might be interested in

A gold bar has a volume of 4.7cm cubed and a density of 19.3 g/cm cubed. What is it’s mass?

joja [24]

Explanation:

Mass = density × volume

m = 19.3 g/cm³ × 4.7 cm³

m = 90.7 g

Round as needed.

7 0

3 years ago

Two wheels have the same mass and radius of 4.4 kg and 0.48 m, respectively. One has (a) the shape of a hoop and the other (b) t

abruzzese [7]

Answer:

1) $\sum T_{externalhoop}=0.4418Nm$

2) $\sum T_{externaldisc}=0.2209Nm$

Explanation:

Using the second equation of angular motion we have

$\theta =\omega _{o}t+\frac{1}{2}\alpha t^{2}$

Since the wheels start from rest we ahve $omega _{o}=0$

Applying the given values in the equation we have

$14=\frac{1}{2}\alpha \times 8^{2}\\\\\therefore \alpha =\frac{28}{64}=0.4375rad/s^{2}$

Now by newton's second law of motion in angular motion we have

$\sum T_{external}=I\alpha$

1) For Hoop We have

$I_{hoop}=Mr^{2}\\\\\therefore I_{hoop}=4.4\times(0.48)^{2}=1.01376kgm^{2}$

Thus

$\sum T_{external}=1.01376\times 0.4375$

$\sum T_{external}=0.4418Nm$

2)For disc We have

$I_{disc}=\frac{Mr^{2}}{2}\\\\\therefore I_{hoop}=2.2\times(0.48)^{2}=0.506kgm^{2}$

Thus

$\sum T_{external}=0.506\times 0.4375$

$\sum T_{external}=0.2209Nm$

5 0

4 years ago

describe how light reflecting from a mirror can produce an image. In particular, explain how mirrors can produce images that are

VikaD [51]

Answer:

A larger image is produced when $d_i$ > $d_o$

A smaller image is produced when $d_i$ < $d_o$

An upright image is produced when m is positive

An upright image is produced when m is negative

Explanation:

The mirror equation is given as follows;

$\dfrac{1}{f} = \dfrac{1}{d_i} + \dfrac{1}{d_o}$

$m =-\dfrac{d_i}{d_o} = \dfrac{h_i}{h_o}$

For concave mirrors, f = focal length

$d_i$ = Image distance from the mirror (-ve $d_i$ = Image is behind the mirror +ve $d_i$ = Image is in front of the mirror)

$d_o$ = Object distance from the mirror (-ve $d_o$ = Object is behind the mirror +ve $d_o$ = Object is in front of the mirror)

m = Magnification (-ve m = Inverted image +ve m = upright image)

$h_i$ = Image height

$h_o$ = Object height

f = Focal length of the mirror

To produce a larger image $d_i$ > $d_o$

To produce a smaller image $d_i$ < $d_o$

To produce an upright image, m should be positive hence, $d_i$ will be negative or the image will appear behind the mirror

To produce an inverted image, m should be negative hence, $d_i$ will be positive or the image will form in front of the mirror.

5 0

3 years ago

The position of a 2.2 kg mass is given by x=(2t3â5t2) m, where t is in seconds.

Juliette [100K]

B b b b b b b bb bb bb b b b b b b b b b

6 0

3 years ago

How strong an electric field is needed to accelerate electrons in an X-ray tube from rest to one-tenth the speed of light in a d

Bond [772]

Answer:

E= 50.1*10³ N/C

Explanation:

Assuming no other forces acting on the electron, if the acceleration is constant, we can use the following kinematic equation in order to find the magnitude of the acceleration:

$vf^{2} -vo^{2} = 2*a*x$

We know that v₀ = 0 (it starts from rest), that vf = 0.1*c, and that x = 0.051 m, so we can solve for a, as follows:

$a = \frac{vf^{2}}{2*x} = \frac{(3e7 m/s)^{2} }{2*0.051m} =8.8e15 m/s2$

According to Newton's 2nd Law, this acceleration must be produced by a net force, acting on the electron.

Assuming no other forces present, this force must be due to the electric field, and by definition of electric field, is as follows:

F = q*E (1)

In this case, q=e= 1.6*10⁻19 C

But this force, can be expressed in this way, according Newton's 2nd Law:

F = m*a (2) ,

where m= me = 9.1*10⁻³¹ kg, and a = 8.8*10¹⁵ m/s², as we have just found out.

From (1) and (2), we can solve for E, as follows:

$E=\frac{me*a}{e} =\frac{(9.1e-31 kg)*(8.8e15m/s2)}{1.6e-19C} = 50.1e3 N/C$

⇒ E = 50.1*10³ N/C

3 0

4 years ago