Does a physical change affect the identity of a substance? Does a chemical change affect the identity of a substance?

Calculate the maximum capillary rise/fall of mercury in a 0.5 mm radius glass capillary. Assume that the surface tension for mer

tekilochka [14]

Answer: 0.01 m

Explanation: The formulae for capillarity rise or fall is given below as

h = (2T×cosθ)/rpg

Where θ = angle mercury made with glass = 50°

T = surface tension = 0.51 N/m

g = acceleration due gravity = 9.8 m/s²

r = radius of tube = 0.5mm = 0.0005m

p = density of mercury.

h = height of rise or fall

From the question, specific gravity of density = 13.3

Where specific gravity = density of mercury/ density of water, where density of water = 1000 kg/m³

Hence density of mercury = 13.3×1000 = 13,300 kg/m³.

By substituting parameters, we have that

h = 2×0.51×cos 50/0.0005×9.8×13,300

h = 0.6556/65.17

h = 0.01 m

8 0

2 years ago

Why does a gymnast rub powder on his hands before exercising on a set of parallel bars? (I need a scientific answer)

dlinn [17]

Answer

To increase friction for a better grip.

Answer

Most human beings do sweat hands especially on the palm. When this happens the person will not have a good grip of heavy objects because they will slide/slip from the hand.

By applying the powder, you are trying to make the hand dry hence increasing the friction for a better grip.

If the gymnast doesn't do this the parallel bars may slip from the hands and injure himself or herself.

4 0

2 years ago

Read 2 more answers

¿ Cuáles son los principales aportes de las ciencias en el desarrollo del mundo? Menciona una aplicación de Física del contenido

maria [59]

Answer:earth, water, air, fire, and (later) aether, which were proposed to explain the nature and complexity of all matter in terms of simpler substances.

Explanation:

3 0

2 years ago

A 20-kg sled is being pulled along the horizontal snow-covered ground by a horizontal force of 26 n. starting from rest, the sle

Vesna [10]

Good morning.

We calculate the acceleration with the Torricelli equation:

$\star\ \boxed{\mathsf{V^2 = V_0^2 + 2a\Delta S}}$

We see that:

$\begin{cases}\mathsf{V_0 = 0}\\\mathsf{V = 2.3 \ m/s}\\\mathsf{\Delta S = 8.9 \ m}\end{cases}$

Now:

$\mathsf{(2.3)^2 = 0^2 + 2a\cdot 8.9}\\ \\ \mathsf{5.29 = 17.8a}\\ \\ \bold{\mathsf{a = 0.3 \ m/s^2}}$

Now we can calculate the resultant force that makes that acceleration of 0.3 m/s² with the 2nd Law of Newton:

$\mathsf{F_r = m\cdot a}\\ \\ \mathsf{F_r = 20\cdot 0.3}\\ \\ \mathsf{F_r = 6 \ N}$

We have a force of 26 N → and a friction force F ←. Adding those vectors, he have a force 6 N →. Therefore:

26 - F = 6

F = 20 N

We have a friction force of 20 N. We calculate the kinect coefficient with the formula:

$\star \ \boxed{\mathsf{F = \mu_k N}}$

Since we are in a horizontal plane, we hava that N = P = mg = 200 N

Therefore:

$\mathsf{20 = \mu_k 200}\\ \\ \boxed{\boxed{\mathsf{\mu_k = 0.1}}}$

5 0

2 years ago

A 0.110 m radius, 506-turn coil is rotated one-fourth of a revolution in 4.17 ms, originally having its plane perpendicular to a

8090 [49]

Answer:

Explanation:

Expression for emf induced = 1 /2 B n r²ω where B is magnetic field , r is radius of the coil and ω is angular velocity of rotation , n is no of turn .

ω = 2πf = 2π x 60 = 120 π ; where f is frequency of rotation .

emf induced = 1 /2 B r²x 120π x n

Putting the given values

10000 = .5 x B x .11² x 120 x 3.14 x 506

B = 8.67 T .

3 0

2 years ago