Remember velocity = distance/time so that mean you would do 60/3 which equals 20 so the speed(velocity) equals 20
Answer:

Explanation:
The ideal gas law equation is an equation that relates some of the quantities that describe a gas: pressure, volume and temperature.
The equation is:

where
p is the pressure of the gas
V is the volume of the gas
n is the number of moles of the gas
R is the gas constant
T is the absolute temperature of the gas (must be expressed in Kelvin)
Here we want to solve the equation isolating p, the pressure of the gas.
We can do that simply by dividing both terms by the volume, V. We find:

So, we see that:
- The pressure is directly proportional to the temperature of the gas
- The pressure is inversely proportional to the volume of the gas
That looks like cells of a multicellular organism, so B.
Answer:
36,000 miles in one hour.
Explanation:
Because there are 60 seconds in a minute and 60 minutes in an hour so to find out how many seconds are in an hour you multipy 60x60 to get 3600. Then to find out how many miles in the 3600 seconds you multiply 10 x 3600 to get 36000.
Mg reaction with O₂ gas will produce MgO so the equation will be
2Mg+O₂⇒2MgO. (You have to find the equation in order two figure out the number of moles of O₂ that will react with 1 mole of MgO).
The first step is to find the number of moles of Mg in 4.03g of Mg. You can do this by dividing 4.03g Mg by its molar mass (which is 24.3g/mol) to get 0.1658mol Mg. Then you have to find the number of moles of O₂ that will react with 0.1658mol Mg. To do this you need to use the fact that 1mol O₂ will react with 2mol Mg (this reatio is from the chemical equation) so you have to multiply 0.1658mol Mg by (1mol O₂)/(2mol Mg) to get 0.0829mol O₂. From here you would usually use PV=nRT and solve for V However, the question tells us that we are at STP, that means you can use the fact that 22.4L of gas is 1 mol of gas at STP. Using that information we can find the volume of O₂ gas by mulitlying 0.0829mol O₂ by 22.4L/mol to get 1.857L which equals 1857mL.
therefore, 1857mL of O₂ gas will react with 4.03g of Mg.
I hope this helps. Let me know in the comments if anything is unclear.