All categories

3 years ago

Is chalk a colloid, suspension, element, compound, or a mixture

1 answer:

3 0

I think that chalk is a compound. it is made up of molecules containing one calcium atom ,one carbon atom and three oxygen atoms.

You might be interested in

How high up is a 5kg object that has 300j of energy

Eddi Din [679]

-- If the object is moving with speed of 10.954 meters per second, then
it has 300J of kinetic energy no matter where it may be located.

-- If the object is 6.118 meters above somewhere, then it has 300J of
gravitational potential energy relative to that place.

7 0

3 years ago

The force of gas particles against the walls of a container is called ________

Liono4ka [1.6K]

Answer:

the answer is pressure

8 0

3 years ago

A firefighting crew uses a water cannon that shoots water at 25.0 m/s at a fixed angle of 53.0° above the horizontal. The fire-f

zysi [14]

Answer:

8.8 m and 52.5 m

Explanation:

The vertical component and horizontal component of water velocity leaving the hose are

$v_v = vsin(\alpha) = 25sin(53^0) = 25*0.8 = 19.97 m/s$

$v_h = vcos(\alpha) = 25cos(53^0) = 25*0.6 = 15 m/s$

Neglect air resistance, vertically speaking, gravitational acceleration g = -9.8m/s2 is the only thing that affects water motion. We can find the time t that it takes to reach the blaze 10m above ground level

$s = v_vt + gt^2/2$

$10 = 19.97t - 9.8t^2/2$

$4.9t^2 - 19.97t + 10 = 0$

$t= \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$

$t= \frac{19.9658877511823\pm \sqrt{(-19.9658877511823)^2 - 4*(4.9)*(10)}}{2*(4.9)}$

$t= \frac{19.9658877511823\pm14.24}{9.8}$

t = 3.49 or t = 0.58

We have 2 solutions for t, one is 0.58 when it first reach the blaze during the 1st shoot up, the other is 3.49s when it falls down

t is also the times it takes to travel across horizontally. We can use this to compute the horizontal distance between the fire-fighters and the building

$s_1 = v_ht_1 = 15*0.58 = 8.8 m$

$s_2 = v_ht_2 = 15*3.49 = 52.5m$

8 0

3 years ago

A 39.3 g glass thermometer reads 22.0oC before it

ratelena [41]

Answer:

44.85C

Explanation:

Let the specific heat of glass thermometer be 0.84 J/g°C

Let the specific heat of water be 4.186 j/g °C

Let the water density be 1kg/L

136 mL of water = 0.136L of water = 0.136 kg of water = 136 g of water

Since the change of temperature on the glass thermometer is 43.6 - 22 = 21.6 C. We can then calculate the heat energy absorbed to it:

$E = m_gc_g \Delta T = 39.3 * 0.84 * 21.6 = 713.06 J$

Assume no energy is lost to outside, by the law of energy conservation, this heat energy would come from water

$E = m_wc_w(T - T_w) = 713.06$

$136*4.186(T - 43.6) = 713.06$

$T - 43.6 = \frac{713.06}{136*4.186} = 1.25$

$T = 1.25 + 43.6 = 44.85C$

6 0

3 years ago

In a weekly project update meeting, Liza asks the following questions of one of her employees: "Why were you late meeting your l

Aleonysh [2.5K]

Answer: This type of questions are called probing questions. The correct option is D.

Explanation:

Probing questions are the type of questions that are asked to investigate an ongoing event. It helps the investigator to know more about what is happening and how to obtain conclusive decisions through the personal opinions of the respondent . For example from the question, Liza wanted to know more about the project updates which was held in the weekly meetings. She asked her employees questions like:

- Why were you late meeting your last deadline?

-Were there external factors that delayed your work?

-Did other coworkers get their part of the assignment to you on time?

- Do you need more help from me?".

7 0

3 years ago