Answer:252 miles
Explanation:
Given
During his way to mountain it took 7 hr to drive
and during his return trip it took 4 hr to return
Let x be the distance between home and mountain
average speed for return is 27 miles per hour faster than his former trip
let v be the speed on his way to mountain thus v+27 is his return speed
thus 
----1
for return trip
-----2
divide 1 & 2
thus 
Construction, like building a home/building, digging, like in a mine, and opening a soda can, where the part to open is a lever.
Clock wise idk i think you should double check my answer
First, find how many copper atoms make up the ball:
moles of atoms = (49.3 g) / (63.5 g per mol of atoms) = 0.<span>77638</span><span>mol
</span> # of atoms = (0.77638 mol) (6.02 × 10^23 atoms per mol) = 4.6738*10^23<span> atoms </span>
<span> There is normally one electron for every proton in copper. This means there are normally 29 electrons per atom:
</span> normal # electrons = (4.6738 × 10^23 atoms) (29 electrons per atom) = <span>
<span>1.3554</span></span><span>× 10^25 electrons
</span>
<span> Currently, the charge in the ball is 2.0 µC, which means -2.0 µC worth of electrons have been removed.
</span><span> # removed electrons = (-2.0 µC) / (1.602 × 10^-13 µC per electron) = 1.2484 × 10^13 electrons removed
</span><span> # removed electrons / normal # electrons = </span>
<span>(1.2484 × 10^13 electrons removed) / (1.3554 × 10^25 electrons) = 9.21 × 10^-13 </span>
<span> That's 1 / 9.21 × 10^13 </span>
