Question 16 of 25

What should a student do if the hydrochloric acid splashes in their eyes? .

gayaneshka [121]

First aid suggestions include:

Hold your face under running water for 15 to 20 minutes and allow the water stream to flood into your eyes. Use your fingers to hold your eyelids apart (make sure there is no trace of the chemical on your fingers).

If you wear contact lenses, remove them as soon as possible.

Seek immediate medical advice. Medical staff will need to know what chemical was involved, particularly whether it was acid or alkaline, liquid or powder.

Do not judge the seriousness of your eye injury on the degree of pain. For example, alkali chemicals don’t usually cause significant symptoms, but can seriously damage the eye.

Powder or particulate (granular matter, like wet concrete) chemicals can be particularly damaging since they are more difficult to flush out.

3 0

2 years ago

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A hypodermic needle consists of a plunger of circular cross-section that slides inside a hollow cylindrical syringe. when the pl

Blababa [14]

The fluid that is being passed through the syringe and needle is incompressible, which means that it will transmit pressure equally. Therefore, the pressure on the plunger will be equivalent to the pressure on the needle. We also know that:

Pressure = Force / Area

Pressure on plunger = 4 / (π*(0.012/2)²)
Pressure on plunger = 35.4 kPa
Pressure on needle = 35.4 kPa

35.4 kPa = F / (4 / (π*(0.0025/2)²)
F = 0.17 N

The force on the needle is 0.17 N

4 0

3 years ago

A meter stick is held vertically with one end on the floor and is then allowed to fall. Find the speed of the other end when it

Tems11 [23]

Answer:

5.4 ms⁻¹

Explanation:

Here we have to use conservation of energy. Initially when the stick is held vertical, its center of mass is at some height above the ground, hence the stick has some gravitational potential energy. As the stick is allowed to fall, its rotates about one. gravitational potential energy of the stick gets converted into rotational kinetic energy.

$L$ = length of the meter stick = 1 m

$m$ = mass of the meter stick

$w$ = angular speed of the meter stick as it hits the floor

$v$ = speed of the other end of the stick

we know that, linear speed and angular speed are related as

$v = r w\\w = \frac{v}{r}$

$h$ = height of center of mass of meter stick above the floor = $\frac{L}{2} = \frac{1}{2} = 0.5 m$

$I$ = Moment of inertia of the stick about one end

For a stick, momentof inertia about one end has the formula as

$I = \frac{mL^{2} }{3}$

Using conservation of energy

Rotational kinetic energy of the stick = gravitational potential energy

$(0.5) I w^{2} = mgh\\(0.5)(\frac{mL^{2} }{3}) (\frac{v}{L} )^{2} = mgh\\(0.5)(\frac{v^{2} }{3}) = gh\\(0.5)(\frac{v^{2} }{3}) = (9.8)(0.5)\\v = 5.4 ms^{-1}$

7 0

3 years ago

While driving down his street one evening, Jonah notices that his neighbor has laid out an electric fan for the garbage to pick

Kryger [21]

Answer: I have no idea either i need help aswell

Explanation:

4 0

2 years ago

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A gas, behaving ideally, has a pressure P1 and at a volume V1. The pressure of the gas is changed to P2. Using Avogadro’s, Charl

Bond [772]

Answer:

Boyle's Law

$\therefore P_1.V_1=P_2.V_2$

Explanation:

Given that:

initially:

pressure of gas, $= P_1$

volume of gas, $= V_1$

finally:

pressure of gas, $= P_2$

volume of gas, $= V_2$

To solve for final volume $V_2$

According to Avogadro’s law the volume of an ideal gas is directly proportional to the no. of moles of the gas under a constant temperature and pressure.

According to the Charles' law, at constant pressure the volume of a given mass of an ideal gas is directly proportional to its temperature.

But here we have a change in the pressure of the Gas so we cannot apply Avogadro’s law and Charles' law.

Here nothing is said about the temperature, so we consider the Boyle's Law which states that at constant temperature the volume of a given mass of an ideal gas is inversely proportional to its pressure.

Mathematically:

$P_1\propto \frac{1}{V_1}$

$\Rightarrow P_1.V_1=k\ \rm(constant)$

$\therefore P_1.V_1=P_2.V_2$

5 0

3 years ago