Look at the tenths place.
If it's less than 5, round down.
If it's greater than 5, round up.
If it's equal to 5. look at the next digit and round that to see if you should round up or down. Then, if it's the last digit, round up.
3 is less than 5, so round down.
67 - 1 = 66 grams.
Mech waves: travel is faster as density of matter increases
EM waves: can pass through matter, travel is slowed as density of matter increases
I think that's all, tell me if I missed anything.
The magnetic force acting on the proton is

where
q is the proton charge
v is its speed
B is the intensity of the magnetic field

is the angle between the direction of v and B; since the proton is moving perpendicular to the magnetic field,

and

, so the force becomes

this force provides the centripetal force that keeps the proton in circular motion:

where the term on the left is the centripetal force, with
m being the mass of the proton
r the radius of its orbit
Re-arranging the previous equation, we can find the radius of the proton's orbit:

And now we can calculate the centripetal acceleration of the proton, which is given by
Tha atmosphere has no effect on gravity.