The word focus means ______

The smallest particle of an element that retains the characteristics of the element is a(n) ________

Novay_Z [31]

//////////“atom”//////////

5 0

3 years ago

A physicist makes a cup of instant coffee and notices that, as the coffee cools, its level drops 3.00 mm in the glass cup. Show

motikmotik

Answer:

Decrease in level by thermal contraction = 0.0076 mm

Drops in level = 3 mm

Therefore The decrease in level is not due to thermal contraction

Explanation:

From linear expansivity,

L₂ = L₁ +(1 + αΔT).............................. equation 1

Where L₂ = final length (m), L₁ = initial length, α = linear expansivity of liquid, ΔT = change in temperature.

Where L₁ = level of coffee in the glass cup = V/(πd²)/4..................... equation 2

L₁ = 4V/πd², where V= Volume of coffee, d = diameter of the cup,

L₁ = 350cm³, d = 7.00cm, and π = 22/7 = 3.143

applying these values in equation 2 above,

∴ L ₁=( 4×350)/(3.143×7²)

L₁ = 9.09

α = γ/3 Where γ = Volumetric expansion coefficient of liquid. = 0.00005/°C

α = 0.00005/3 = 0.0000167/°C, ΔT = L₂ - L₁ = 45 -95 = -50 °C.

Applying these values in equation 1 above,

L₂ = 9.09 [1+{0.0000167×(-50)}]

L₂ = 9.09 [1 - 0.000833]

L₂ = 9.09(0.999167)

L₂ = 9.082cm

∴ ΔL = Decrease in length = L₂ - L₁ = 9.082 - 9.09 = 0.3 cm

ΔL = 0.0076

Decrease in level =0.076 mm

From the above, the decrease in level is not due to thermal contraction.

As Thermal contraction is less than Drops in level.

4 0

3 years ago

A massless string connects a 1.00 kg mass to a 3.00 kg cart which is resting on a frictionless horizontal surface. The mass hang

Romashka-Z-Leto [24]

Both masses will have the same acceleration. The cart accelerates to the right with a magnitude of 4.9 m/ $s^{2}$ . The correct answer is 4.90 m/ $s^{2}$

Given that a massless string connects a 1.00 kg mass to a 3.00 kg cart which is resting on a frictionless horizontal surface.

Let M = 1kg and m = 3 kg

Since the horizontal surface is frictionless, the tension in the string will be the same. when the mass is hanged over a frictionless pulley, the tension will also be the same.

When the mass is released, the cart accelerates to the right can be calculated from Newton' second law of motion. That is,

M( g + a) = m(g - a)

1(9.8 + a) = 3( 9.8 - a)

9.8 +a = 29.4 - 3a

collect the like terms

4a = 19.6

a = 19.6/4

a = 4.9 m/ $s^{2}$

Therefore, the cart accelerates to the right with a magnitude of 4.9 m/ $s^{2}$ . The correct answer is 4.90 m/ $s^{2}$

Learn more about dynamics here: brainly.com/question/24994188

5 0

2 years ago

Whats the answer to this question show in the picture

devlian [24]

Answer:

The answer is 10 m/s

The difference between mass and weight is that mass is the amount of matter in a material while weight is a measure of how the force of gravity acts upon that mass.

4 0

3 years ago

The work done on an ideal gas system in an isothermal process is -400J. What is the change in internal (thermal) energy of the g

denpristay [2]

Answer:

The change in internal energy is zero.

(a) is correct option

Explanation:

Given that,

Work done W = -400 J

The First law of thermodynamics is law conservation of energy

Law of conservation energy is defined the total amount of energy is constant in isolated system.

The energy can not be created and destroyed but the energy can be changed from one form to other form.

The First law of thermodynamics is given by

$\Delta U=Q+W$

Where,

W = work done by the system or on the system

$\Delta U$ = Total internal energy

Q = heat

In isothermal process, the temperature is constant

The energy can not be change and the internal energy is the function of temperature.

So, The internal energy will be zero .

Hence, The change in internal energy is zero.

7 0

3 years ago

The word focus means _______.