As I am reading the problem, I see they gave you two pressures, one volume and they are asking for another volume. this should give you a hint that you need to use the following formula.
P1V1= P2V2
P1= 1.00 atm
V1= 0.50 ft³
P2= 3.00 atm
V2= ?
Now we plug the values
(1.00 x 0.50)= (3.00 x V2)
V2= 0.17 ft³
Answer:
Kinetic energy: 
Velocity: 
Explanation:
From the equations of the photo-electric effect,
We know:

Where,
1.
is the Planck's constant which is 
2.
are the frequency of light emitted and threshold frequencies respectively.
3.
is the kinetic energy of the electrons emitted.
By fact, we come to know that the threshold frequency of Zn is 300nm
And also
Where ,
1.
is the speed of light 
2.
is the wavelength.
Thus,

Now to find velocity:

Incomplete question. The remaining part reads;
Choose the correct words or phrases to complete the sentences.
Global winds occur due to
<u>1. Choose...</u>
a. solar currents
b. convection currents
c. sea breezes
d. uneven heating
over a large area and this forms
2. Choose...
a. solar currents
b. convection currents
c. sea breezes
d. uneven heating
caused by cool and warm air.
Answer:
<u>1. d. uneven heating</u>
<u>2. b. convection currents</u>
Explanation:
1. What Beto should know is that as the earth moves and rotates around the sun, some parts of the Earth receive more sunlight and others less, which then leads to uneven heating over a large area of the earth.
2. This uneven heat then forms a convection current containing varying patterns of air spreading to various parts of the globe.
3.4 X 10^-2 because you start your equation with 2.5g in your (what we call train tracks). Then you have to find the GFM (gram formula mass) of KCl (potassium chloride). You find this by adding the average atomic mass of each element. Potassium's is 39.10 and Chlorine's is 35.45 which gives you a total of 74.55 grams per mol. so now that you have found the GFM you plug that number into the diagonal bottom in order to cancel the gram units. Then you would place 1 mol KCl on top because that is the unit you want. Finally you will divide your original 2.5 by the GFM of 74.55 to get an answer of 0.033534 mol KCl... but since sig figs matter your final answer will be 3.4 X 10^-2