If sunlight begins to warm a frozen lake, the atoms in the lakes frozen water will begin to move faster. True of False?

What is Newton’s third law?

ch4aika [34]

Answer:

For every action, there is an equal and opposite reaction

Explanation:

7 0

3 years ago

7. A force stretches a wire by 1 mm. a. A second wire of the same material has the same cross section and twice the length. How

Lera25 [3.4K]

Answer:

(a) The second wire will be stretched by 2 mm

(b) The third wire will be stretched by 0.25 mm

Explanation:

Tensile stress on every engineering material is given as the ratio of applied force to unit area of the material.

σ = F / A

Tensile strain on every engineering material is given as the ratio of extension of the material to the original length

δ = e / L

The ratio of tensile stress to tensile strain is known as Young's modulus of the material.

$Y = \frac{FL}{Ae}$

Part A

cross sectional area and applied force are the same as the original but the length is doubled

$\frac{FL_1}{A_1e_1} = \frac{FL_o}{A_oe_o} \\\\\frac{L_1}{e_1} = \frac{L_o}{e_o}\\\\e_1 = \frac{L_1e_o}{L_o} \\\\But, L_1 =2L_o\\\\e_1 = \frac{2L_oe_o}{L_o}\\e_1 = 2e_o$

The second wire will be stretched by 2 mm

Part B

a third wire with the same length but twice the diameter of the first

$\frac{FL}{A_1e_1} = \frac{FL}{A_oe_o} \\\\\frac{1}{A_1e_1} = \frac{1}{A_oe_o}\\\\\frac{4}{\pi d_1^2e_1} = \frac{4}{\pi d^2_oe_o}\\\\\frac{1}{d_1^2e_1} = \frac{1}{d^2_oe_o}\\\\d_1^2e_1 = d^2_oe_o\\\\e_1 = \frac{d^2_oe_o}{d_1^2} \\\\e_1 =(\frac{d_o}{d_1})^2e_o\\\\But, d_1 = 2d_o\\\\e_1 =(\frac{d_o}{2d_o})^2e_o\\\\e_1 =(\frac{1}{2})^2e_o\\\\e_1 =(\frac{1}{4})e_o$

e₁ = ¹/₄ x 1 mm = 0.25 mm

The third wire will be stretched by 0.25 mm

3 0

4 years ago

Calculate the temperature increase in a 1.00-kg sample of water that results from the conversion of gravitational potential ener

Llana [10]

To solve this problem it is necessary to apply the concepts concerning the conservation of both potential and thermodynamic energy of the body. That is to say that as the body has a loss of potential energy it is gained in the form of thermal energy on water. If the potential energy is defined as

$PE = mgh$

Where,

m= mass

g = Gravitational acceleration

h = Height

And thermal energy is obtained as

$Q = mC_p\Delta T$

Where,

$\Delta T$ = Change in Temperature

$C_p =$ Specific Heat

m = Mass

We can equate this equation and rearrange to find the change at the Temperature, then

$mgh = mC_p\Delta T$

$\Delta T = \frac{gh}{C_p}$

Our values are given as,

$C_p = 4186J/Kg\cdot K \rightarrow$ Specific Heat Water

Using energy conservation

$g = 9.8m/s^2$

$h = 807m$

Replacing,

$\Delta T = \frac{(9.8)(807)}{4186}$

$\Delta T = 1.89K$

Therefore the temperature increase in a 1kg sample of water is 1.89K

8 0

3 years ago

uring the investigation of a traffic accident, police find skid marks 89.9 m long. They determine the coefficient of friction be

aivan3 [116]

Answer:

$V_{0}=29.68m/s$

Explanation:

In order to solve this problem, we must first do a drawing of the situation (see attached picture).

When the brakes of the car were applied, we can see that there was only one horizontal force affecting the vehicle's movement, which was the force of friction. When analyzing the free body diagram we can apply Newton's laws to determine the equations we will use to solve this.

$\sum F_{x}=ma$