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3 years ago

Pleasse help

Physics

2 answers:

GaryK [48]3 years ago

3 0

Hi,

The correct answer is letter B.

The last group contains noble gases, while both along the top and along the bottom the elements on the right are non-metals.

inn [45]3 years ago

3 0

Answer:

Group 2

Explanation:

The second group consists of only alkaline earth metals, because it posses beryllium, magnesium, calcium, strontium, barium, and radium.

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You jump off a truck and accelerate toward the surface of the Earth. Does the Earth accelerate toward you?

Triss [41]

When we jump from the truck and accelerate towards the earth surface, the earth also accelerates towards us but it's acceleration is very negligible.

To find the answer, we need to know about the acceleration of earth due to the gravitational attraction.

<h3>What's the gravitational force between the earth and a person?</h3>

Gravitational attraction force is GMm/r² between the earth and a person.
M= mass of the earth

m= mass of the person

r= separation between them.

<h3>What's the acceleration of the earth towards the person when he jumps from a truck?</h3>

According to Newton's second law, Force = M×acceleration
Acceleration= Force / M
Here, Force = GMm/r²,

so acceleration of earth= Gm/r²

As this acceleration is very small, so we can't notice it.

Thus, we can conclude that the earth also accelerates towards us.

Learn more about the gravitational force here:

brainly.com/question/72250

#SPJ4

7 0

2 years ago

A merry-go-round with a rotational inertia of 600 kg m2 and a radius of 3. 0 m is initially at rest. A 20 kg boy approaches the

Margaret [11]

Hi there!

$\boxed{\omega = 0.38 rad/sec}$

We can use the conservation of angular momentum to solve.

$\large\boxed{L_i = L_f}$

Recall the equation for angular momentum:

$L = I\omega$

We can begin by writing out the scenario as a conservation of angular momentum:

$I_m\omega_m + I_b\omega_b = \omega_f(I_m + I_b)$

$I_m$ = moment of inertia of the merry-go-round (kgm²)

$\omega_m$ = angular velocity of merry go round (rad/sec)

$\omega_f$ = final angular velocity of COMBINED objects (rad/sec)

$I_b$ = moment of inertia of boy (kgm²)

$\omega_b$ = angular velocity of the boy (rad/sec)

The only value not explicitly given is the moment of inertia of the boy.

Since he stands along the edge of the merry go round:

$I = MR^2$

We are given that he jumps on the merry-go-round at a speed of 5 m/s. Use the following relation:

$\omega = \frac{v}{r}$

$L_b = MR^2(\frac{v}{R}) = MRv$

Plug in the given values:

$L_b = (20)(3)(5) = 300 kgm^2/s$

Now, we must solve for the boy's moment of inertia:

$I = MR^2\\I = 20(3^2) = 180 kgm^2$

Use the above equation for conservation of momentum:

$600(0) + 300 = \omega_f(180 + 600)\\\\300 = 780\omega_f\\\\\omega = \boxed{0.38 rad/sec}$

8 0

2 years ago

Given that water at standard pressure freezes at 0∘C, which corresponds to 32∘F, and that it boils at 100∘C, which corresponds t

barxatty [35]

Answer:

In two significant figure 360K

Explanation:

The temperature difference (ΔT) can be calculated as the boiling temperature minus the freezing temperature in Fahrenheit.

Hence,

ΔT = 212 - 32

ΔT = 180°F

To convert to °F to kelvin, we use the formula below

= (°F - 32) × 5/9 + 273.15

= (180°F - 32) × 5/9 + 273.15

= 355.37K ⇔ 360K

3 0

3 years ago

A turtle ambles leisurely, as turtles tend to do, when it moves from a location with position vector 1,=1.91 m and 1,=−2.73 m in

Elena-2011 [213]

Answer:

Components: 0.0057, -0.0068. Magnitude: 0.0089 m/s

Explanation:

The displacement in the x-direction is:

$d_x = 3.65-1.91=1.74 m$

While the displacement in the y-direction is:

$d_y = -4.79 -(-2.73)=-2.06 m$

The time taken is t = 304 s.

So the components of the average velocity are:

$v_x = \frac{d_x}{t}=\frac{1.74}{304}=0.0057 m/s$

$v_y = \frac{d_y}{t}=\frac{-2.06}{304}=-0.0068 m/s$

And the magnitude of the average velocity is

$v=\sqrt{v_x^2+v_y^2}=\sqrt{(0.0057)^2+(-0.0068)^2}=0.0089 m/s$

8 0

3 years ago

In this diagram, which force is represted by L?

Dmitry [639]

Answer is a) the force caused by the wend nag encountering wind and air.

8 0

3 years ago