Ask question

Ask question

All categories

3 years ago

8

Which of the following is true about a family psychologist?

2 answers:

viva [34]3 years ago

7 0

Answer:

1. A family psychologist would help deal with developmental and behavior problems in children and teenagers

3. Family psychologists would typically counsel a couple on the edge of divorce

Explanation:

ikadub [295]3 years ago

3 0

Are there answer choices?

You might be interested in

______ is the most abundant gas in Earth’s atmosphere.

algol13

Answer:

<em>Nitrogen</em>

Explanation:

<u>Composition of the Atmosphere</u>

The atmosphere contains several gases, most of them in small amounts, which may include some pollutants and greenhouse gases.

The most abundant gas in the atmosphere is nitrogen (78%), followed by oxygen (21%) as the second. The inert gas called Argon is the third most abundant gas in the atmosphere (less than 1%).

Finally, the fourth most abundant gas in Earth's atmosphere is Carbon dioxide

4 0

3 years ago

The reaction of magnesium ribbon with oxygen.what is the product formed?

zaharov [31]

When oxygen reacts with magnesium thenMgO3 is formed.

Mg +O2----> MgO3

6 0

3 years ago

A 20-kg block is held at rest on the inclined slope by a peg. A 2-kg pendulum starts at rest in a horizontal position when it is

gregori [183]

Complete Question

The diagram of this question is shown on the first uploaded image

Answer:

The distance the block slides before stopping is $d = 0.313 \ m$

Explanation:

The free body diagram for the diagram in the question is shown

From the diagram the angle is $\theta = 25 ^o$

$sin \theta = \frac{h}{d}$

Where $h = h_b - h_a$

So $d sin \theta = h_b - h_a$

From the question we are told that

The mass of the block is $m = 20 \ kg$

The mass of the pendulum is $m_p = 2 \ kg$

The velocity of the pendulum at the bottom of swing is $v_p = 15 m/s$

The coefficient of restitution is $e =0.7$

The coefficient of kinetic friction is $\mu _k = 0.5$

The velocity of the block after the impact is mathematically represented as

$v_2 f = \frac{m_b - em_p}{m_b + m_p} * v_2 i + \frac{[1 + e] m_1}{m_1 + m_2 } v_p$

Where $v_2 i$ is the velocity of the block before collision which is 0

$= \frac{20 - (0.7 * 2)}{(2 + 20)} * 0 + \frac{(1 + 0.7) * 2 }{2 + 20} * 15$

Substituting value

$v_2 f = 2.310\ m/s$

According to conservation of energy principle

The energy at point a = energy at point b

So $PE_A + KE _A = PE_B + KE_B + E_F$

Where

$PE_A$ is the potential energy at A which is mathematically represented as

$PE_A = m_b gh_a$ = 0 at the bottom

$KE _A$ is the kinetic energy at A which is mathematically represented as

$K_A = \frac{1}{2} m_b * v_2f^2$

$PE_B$ is the potential energy at B which is mathematically represented as

$PE_B = m_b gh$

From the diagram $h = h_b -h_a$

$PE_B = m_b g(h_b - h_a)$

$KE _B$ is the kinetic energy at B which is 0 (at the top )

Where is $E_F$ is the workdone against velocity which from the diagram is

$\mu_k m_b g cos 25 *d$

So

$\frac{1}{2} m_b v_2 f^2 = m_b g h_b + \mu_k m_b g cos \25 * d$

Substituting values

$\frac{1}{2} * 20 * 2.310^2 = 20 * 9.8 * d sin(25) + 0.5* 20 * 9.8 * cos 25 * d$

So

$d = 0.313 \ m$

6 0

3 years ago

A metallic conductor has a resistivity of 35 × 10 −6 Ω⋅m. What is the resistance of a piece that is 20 m long and has a uniform

Nitella [24]

Answer:

Therefore the resistance of the conductor is 175Ω

Explanation:

Resistance:

Resistance of a metallic conductor is directly proportional to its length(l).

Resistance of a metallic conductor is inversely proportional to its cross section area(A).

The notation sign of resistance is R.

The unit of resistance is ohm (Ω).

Therefore,

$R \propto l$

and

$R \propto \frac{1}{A}$

$\therefore R\propto \frac{l}{A}$

$\Rightarrow R=\rho \frac{l}{A}$

ρ is the proportional constant.

It is also known as resistivity of that metal.

Given ρ=35×10⁻⁶Ω-m

l= 20 m

A= 4.0×10⁻⁶m²

$\therefore R=35\times 10^{-6}\times \frac{20}{4.0\times 10^{-6}}$

=175Ω

Therefore the resistance of the conductor is 175Ω

3 0

3 years ago

At the same moment, one rock is dropped and one is thrown downward with an initial velocity of 29m/s from the top of a building

Inessa [10]

Answer:

The thrown rock strike 2.42 seconds earlier.

Explanation:

This is an uniformly accelerated motion problem, so in order to find the arrival time we will use the following formula:

$x=vo*t+\frac{1}{2} a*t^2\\where\\x=distance\\vo=initial velocity\\a=acceleration$

So now we have an equation and unkown value.

for the thrown rock

$\frac{1}{2}(9.8)*t^2+29*t-300=0$

for the dropped rock

$\frac{1}{2}(9.8)*t^2+0*t-300=0$

solving both equation with the quadratic formula:

$\frac{-b\±\sqrt{b^2-4*a*c} }{2*a}$

we have:

the thrown rock arrives on t=5.4 sec

the dropped rock arrives on t=7.82 sec

so the thrown rock arrives 2.42 seconds earlier (7.82-5.4=2.42)

6 0

3 years ago