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3 years ago

Why doesn't the same amount of oil exerts always the same pressure at the bottom of a container of any shape?

1 answer:

3 0

This is a good question. The short (but less satisfying) answer is: "because the hydrostatic pressure of oil at a certain depth depends on the height of the oil level, measured from that point." So, you can have a tiny amount of oil but arranged in a column that makes it very tall/high and get high pressure, and have same amount of oil spread so that the height is negligible to produce a negligible amount of pressure. The exact formula for pressure is P=r*h*g (r stands for the liquid density, h for height, and g for gravitational acceleration).

The long answer, but much more satisfying, goes through the derivation of this formula. I recommend searching for a good video explaining hydrostatic pressure. (I can't post links).

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A person pushes horizontally with a force of 220. N on a 61.0 kg crate to move it across a level floor. The coefficient of kinet

Ede4ka [16]

Answer:

(a) 161.57 N

(b) 0.958 m/s^2

Explanation:

Force applied, F = 220 N

mass of crate, m = 61 kg

μ = 0.27

(a) The magnitude of the frictional force,

f = μ N

where, N is the normal reaction

N = m x g = 61 x 9.81 = 598.41 N

So, the frictional force, f = 0.27 x 598.41

f = 161.57 N

(b) Let a be the acceleration of the crate.

Fnet = F - f = 220 - 161.57

Fnet = 58.43 N

According to newton's second law

Fnet = mass x acceleration

58.43 = 61 x a

a = 0.958 m/s^2

Thus, the acceleration of the crate is 0.958 m/s^2.

7 0

3 years ago

If the potential due to a point charge is 490 V at a distance of 10 m, what are the sign and magnitude of the charge?

uysha [10]

Answer:

+5.4×10⁻⁷ C

Explanation:

Electric potential: This can be defined as the work done in bringing a unit charge from infinity to that point against the action of the field. The S.I unit of potential is volt (V)

The formula for potential is

V = kq/r............................ Equation 1

Where V = electric potential, k = proportionality constant, q = charge, r = distance.

making q the subject of the equation,

q = Vr/k............................ Equation 2

Given: V = 490 V, r = 10 m,

Constant: k = 9×10⁹ Nm²/C²

Substitute into equation 2

q = 490(10)/(9×10⁹)

q = 5.4×10⁻⁷ C

q = +5.4×10⁻⁷ C

Hence the charge is +5.4×10⁻⁷ C

7 0

3 years ago

Determine the ratio of the resistivity of pure water to silver?

shutvik [7]

Silver is a very good conductor, this means its resistivity is very low (from table, we can check the precise value, which is $\rho_s = 1.6 \cdot 10^{-8} \Omega m$ ).

Pure water, instead, is a very bad conductor, this means its resistivity is very high, of order of $k \Omega \cdot m$ ( $10^3 \Omega m$ ). Even without knowing the precise value of the pure water resistivity, we can estimate the ratio between the pure water resistivity and the silver resistivity by comparing the two orders of magnitude:
$r= \frac{10^3 \Omega m}{10^{-8} \Omega m} \sim 10^{11}$

Therefore, we can say that the correct answer is
$3 \cdot 10^{11} : 1$

3 0

3 years ago

Weightlessness is experienced by an astronaut in space. This means that the astronaut's muscles have to be stronger to move his

just olya [345]

The answer is false. The speed of the astronaut cancels out the force of gravity, causing a 'stationary freefall'. While under these effects, it is not required for an astronaut to 'strengthen' his body.

4 0

3 years ago

Read 2 more answers

State two factors that affect the rate of diffusion of a substance

Ronch [10]

Explanation:

Two factors that affect the rater of diffusion of a substance are:

Diffusion of substance plays an important role on cellular transport in plants.
Diffusion is the passive movement of substance from a region of higher concentration to a region of lower concentration.

4 0

3 years ago