PLEASE HELP WITH WORK INCLUDED

A 74 kg zebra is traveling 15 m/s east. What is the zebra’s momentum

svetoff [14.1K]

Mass × velocity = momentum

74 x 15 = momentum

7 0

4 years ago

Calculate how much carbohydrate a 175-pound athlete who is in training 4-5 hours per day should eat each day in order to enhance

Kamila [148]

Answer:

The athlete should consume about 476 g of carbohydrates per day to maintain a good storage of glycogen in his body

Explanation:

For an athlete who trains daily, 5 to 7 g of carbohydrates per Kg of body weight per day is recommended;

∴ m athlete = (175 Lb)×(0.453592 Kg/Lb) = 79.3787 Kg

⇒ m carbohydrate = (79.3787 Kg)×( 6 g carbohydrate/ Kg.day) = 476.27 g carbohydrate/day

5 0

3 years ago

How would you prepare 250 mL of a 0.100 M solution of fluoride ions<br> from solid CaF2?

andrey2020 [161]

In 250 mL of volumetric flask add 0.975875 grams of $CaF_2$ and dissolve it in the 250 mL of water.

Given:

The solid of calcium fluoride.

To prepare:

The 250 mL solution of 0.100 M of fluoride ions from solid calcium fluoride.

Method:

Molarity of the fluoride ion solution needed = M = 0.100 M

The volume of the fluoride ion solution needed = V = 250 mL

$1 mL = 0.001L\\V=250 mL=250\times 0.001 L=0.250 L$

The moles of fluoride ion needed = n

According to the definition of molarity:

$M=\frac{n}{V}\\0.100M=\frac{n}{0.250 L}\\n=0.100M\times 0.250 L=0.025 mol$

Moles of fluoride ion = 0.025 mol

We know that solid calcium fluoride dissolves in water to give calcium ions and fluoride ions.

$CaF_2(s)\rightarrow Ca^{2+}(aq)+2F^-(aq)$

According to reaction, 2 moles of fluoride ions are obtained from 1 mole of calcium fluoride, then 0.025 moles of fluoride ions will be obtained from:

$=\frac{1}{2}\times 0.025 mol=0.0125 \text{mol of } CaF_2$

Moles of calcium fluoride = 0.0125 mol

Mass of calcium fluoride needed to prepare the solution :

$=0.0125 mol\times 78.07 g/mol=0.975875 g$

Preparation:

Weight 0.975875 grams of calcium fluoride
Add weighed calcium fluoride to a volumetric flask of the labeled volume of 250 mL.
Now add a small amount of water to dissolve the calcium fluoride completely.
After this add more water up to the mark of the volumetric flask of volume 250 mL.