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3 years ago

12

Thandy is looking at two cells under the microscope.One is a human cheek cell and the other is a leaf mesophyll cell from a plan

t. Why does thandy need to use a microscope to look at the cells ?

1 answer:

Vanyuwa [196]3 years ago

7 0

Cell are small and us human can't see them with our own eyes. it is in possible to see cell without a microscope

You might be interested in

The volume of a gas is reduced from 4 l to 0.5 l while the temperature is held constant. How does the gas pressure change?

shusha [124]

Answer:

The pressure increases by a factor 8

Explanation:

For a gas held at constant temperature, Boyle's law can be applied. It states that the product of the gas pressure and the gas volume is constant, so we can write:

$p_1 V_1 = p_2 V_2$

where

$p_1$ is the initial pressure

$p_2$ is the final pressure

$V_1$ is the initial volume

$V_2$ is the final volume

For the gas in this problem, the volume is reduced from

$V_1 = 4 L$

to

$V_2 = 0.5 L$

so we can rewrite the equation as

$\frac{p_2}{p_1}=\frac{V_1}{V_2}=\frac{4 L}{0.5 L}=8$

this means that the pressure of the gas will increase by a factor 8.

5 0

4 years ago

Ok sooo I need help I don’t understand this lol

Burka [1]

Answer:

I dont either but I'm sorry and hopefully you figured it out

3 0

3 years ago

Aluminum rivets used in airplane construction are made slightly larger than the rivet holes and cooled by "dry ice" (solid CO2)

poizon [28]

Answer:

$\rm 4.554\ m m.$

Explanation:

<u>Given:</u>

Initial temperature, $\rm T_i=23.0\ ^\circ C=23 + 273.15 = 296.15\ K.$
Final temperature, $\rm T_f = -78.0\ ^\circ C = -78+273.15=195.15\ K.$
Diameter of the hole, $\rm d = 4.500\ m = 4.500\times 10^{-3}\ m.$
Expansion coefficient of the Aluminum, $\rm \alpha = 2.4\times 10^{-5}\ K^{-1}.$

Let the diameter of the rivet at $\rm T_i=23.0\ ^\circ C$ be $\rm d_o$ , such that,

$\rm d_o=d+\Delta d$

$\rm \Delta d$ is the elongation in the diameter of the rivet.

We know, The change in the diameter of the rivet is related with the change in temperature as:

$\rm \dfrac{\Delta d}{d_o}=\alpha \Delta T.$

where, $\rm \Delta T$ is the change in temperature = $\rm T_f-T_i=-195.15-296.15=-491.30\ K.$

Also, $\rm \Delta d=d_o-d.$

Using these values,

$\rm \dfrac{d_o-d}{d_o}=\alpha \Delta T\\1-\dfrac{d}{d_o}=\alpha \Delta T\\\dfrac{d}{d_o}=1+\alpha \Delta T\\\Rightarrow d_o = \dfrac{d}{1+\alpha \Delta T}\\=\dfrac{4.500\times 10^{-3}}{1+2.4\times10^{-5}\times (-491.30)}\\=4.554\times 10^{-3}\ m.\\=4.554\ m m.$

It is the required diameter of the rivet at $-78.0\ ^\circ C$ .

4 0

3 years ago

A forward-biased silicon diode is connected to a 6.0-V battery. Also in the circuit are three 220 Ω resistors connected in serie

o-na [289]

Answer:

Current in the circuit will be 0.024 A

Explanation:

We have given battery voltage v = 6 volt

Resistance R = 220 ohm

Diode potential $v_d$ = 0.7 volt

So voltage across the resistance = 6 - 0.7 = 5.3 volt

Current is given by $current=\frac{voltage}{reistance}=\frac{5.3}{220}=0.024A$

So current in the circuit will be 0.024 A

3 0

3 years ago

An airplane flies with a constant speed<br> of 720 km/h. How far can it travel in<br> 3 hours

Westkost [7]

Answer:

2160 km/h

Explanation:

720 times 3 gives you the answer

5 0

4 years ago