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2 years ago

11

A big kid pushes a little kid and the little kid falls backward. The big kid remains relatively stationary. What best explains t

his

2 answers:

postnew [5]2 years ago

7 0

The big kid is the strongest ?

charle [14.2K]2 years ago

7 0

Answer:

Becase he pushed the little kid not himself

Explanation:

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The number of employees for a certain company has been decreasing each year by 4%. If the company currently has 650 employees an

nika2105 [10]

The answer would probably be 649.96

8 0

3 years ago

Acetone is a flammable solvent used in the making of plastics. The density is 790kg/m3. to convert 790kg/m3 to g/cm3

Artist 52 [7]

Answer: 0.790 g/cm3

Explanation:

The density of acetone is 790 Kg/m3.

To convert from Kg to g we multiply by 1000 (1 Kg = 1000 g)

To convert from m3 to cm3 we multiply by 10∧6

So, The density of acetone in (g/cm3) = (790 x 1000) / (10∧6) = 0.79 g/cm3

4 0

3 years ago

2200 kg semi truck driving down the highway has lost control. The truck rolls across the median and into oncoming traffic. The t

serious [3.7K]

Answer:

The semi truck travels at an initial speed of 69.545 meters per second downwards.

Explanation:

In this exercise we see a case of an entirely inellastic collision between the semi truck and the car, which can be described by the following equation derived from Principle of Linear Momentum Conservation: (We assume that velocity oriented northwards is positive)

$m_{S}\cdot v_{S}+m_{C}\cdot v_{C} = (m_{S}+m_{C})\cdot v$ (1)

Where:

$m_{S}$ , $m_{C}$ - Masses of the semi truck and the car, measured in kilograms.

$v_{S}$ , $v_{C}$ - Initial velocities of the semi truck and the car, measured in meters per second.

$v$ - Final speed of the system after collision, measured in meters per second.

If we know that $m_{S} = 2200\,kg$ , $m_{C} = 2000\,kg$ , $v_{C} = 45\,\frac{m}{s}$ and $v = -15\,\frac{m}{s}$ , then the initial velocity of the semi truck is:

$m_{S}\cdot v_{S} = (m_{S}+m_{C})\cdot v -m_{C}\cdot v_{C}$

$v_{S} = \frac{(m_{S}+m_{C})\cdot v - m_{C}\cdot v_{C}}{m_{S}}$

$v_{S} = \left(1+\frac{m_{C}}{m_{S}} \right)\cdot v - \frac{m_{C}}{m_{S}} \cdot v_{C}$

$v_{S} = v +\frac{m_{C}}{m_{S}}\cdot (v-v_{C})$

$v_{S} = -15\,\frac{m}{s}+\left(\frac{2000\,kg}{2200\,kg} \right) \cdot \left(-15\,\frac{m}{s}-45\,\frac{m}{s} \right)$

$v_{S} = -69.545\,\frac{m}{s}$

The semi truck travels at an initial speed of 69.545 meters per second downwards.

3 0

2 years ago

A specimen of steel has a rectangular cross section 20 mm wide and 40 mm thick, an elastic modulus of 207 GPa, and a Poisson’s r

katrin2010 [14]

Answer:

There's a decrease in width of 2.18 × 10^(-6) m

Explanation:

We are given;

Shear Modulus;E = 207 GPa = 207 × 10^(9) N/m²

Force;F = 60000 N.

Poisson’s ratio; υ =0.30

We are told width is 20 mm and thickness 40 mm.

Thus;

Area = 20 × 10^(-3) × 40 × 10^(-3)

Area = 8 × 10^(-4) m²

Now formula for shear modulus is;

E = σ/ε_z

Where σ is stress given by the formula Force(F)/Area(A)

While ε_z is longitudinal strain.

Thus;

E = (F/A)/ε_z

ε_z = (F/A)/E

ε_z = (60,000/(8 × 10^(-4)))/(207 × 10^(9))

ε_z = 3.62 × 10^(-4)

Now, formula for lateral strain is;

ε_x = - υ × ε_z

ε_x = -0.3 × 3.62 × 10^(-4)

ε_x = -1.09 × 10^(-4)

Now, change in width is given by;

Δw = w_o × ε_x

Where w_o is initial width = 20 × 10^(-3) m

So; Δw = 20 × 10^(-3) × -1.09 × 10^(-4)

Δw = -2.18 × 10^(-6) m

Negative means the width decreased.

So there's a decrease in width of 2.18 × 10^(-6) m

6 0

3 years ago

psychology chapter 7, principles of learning; I am the process whereby animals are taught a complicated response by being reward

jeyben [28]

<span>Answer: Burrhus Frederic Skinner's Operant Conditioning.

</span><span>B.F. Skinner believed that to understand behavior, in the best way, is to look at the root causes or reasons of an action and its outcomes.
</span>
Skinner proposes the Law of Effect-Reinforcement. Here,he differentiated the positively reinforced behavior or the strengthened behavior, the negatively reinforced behavior (removal of the unpleasant experience), and weakened behavior because of punishment.
<span>
In positive reinforcement, behavior is strengthened through providing an outcome, an effect that an individual finds rewarding. Negative reinforcement also strengthens behavior because the unpleasant experience was removed. Punishment on the other hand is an opposite to reinforcement. Instead of increasing the response, it eliminates it or weakens it.
</span>

8 0

3 years ago