Last one! Thankyou for the help thus far...
calculate the KE in kJ of 9.100 x 10^5 atoms of silver moving at 1800. km/hr. ... the atoms part is what I'm confused about.
& this one...
4. A person drops 740 g rock originally held 6.5 ft above the ground. What is its velocity the moment before it hits the gound. (Assume rock doesn't gain/lose energy)... (Hint: You will need to calculate the P.E of the rock before it's dropped!
it's a fraction of a mole
... 9.1E5 / 6.02E23
multiply the fraction by the molar mass
m g h = 1/2 m v^2 ... v = √(2 g h)
To calculate the kinetic energy (KE) of the given number of atoms of silver, we can use the following formula:
KE = (1/2) * m * v^2
Where:
KE is the kinetic energy
m is the mass of the object
v is the velocity of the object
In order to calculate the KE, we need to find the mass of the atoms of silver.
To find the mass of the atoms, we can use the atomic mass of silver (Ag), which is approximately 107.87 grams per mole.
Given that we have 9.100 x 10^5 atoms, we can calculate the mass of these atoms as follows:
Mass of 9.100 x 10^5 atoms of silver in grams = (9.100 x 10^5 atoms) * (1 mole of silver / 6.022 x 10^23 atoms) * (107.87 g / 1 mole)
Now that we have the mass of the atoms, we can convert the velocity from kilometers per hour to meters per second, because the SI unit of velocity is meters per second.
Velocity in m/s = (1800 km/hr) * (1000 m /1 km) * (1 hr / 3600 s)
Next, we can substitute the values into the formula to calculate the kinetic energy:
KE = (1/2) * (mass in grams) * (velocity in m/s)^2
Finally, since the SI unit for energy is joules (J), we can convert the answer from grams to kilograms and from joules to kilojoules.
KE in kJ = (KE in J) / 1000
By following these steps and performing the calculations, you will be able to find the kinetic energy in kJ of the given number of atoms of silver moving at the given velocity.