The formula for a kinetic energy KE of a falling body is
KE = mgh
where m = mass, g = acceleration due to gravity (9.8 m/s^2, constant), h = height.
The total mass of a skateboader and a skateboard is 64 + 2.0 = 66 kg.
Finally,
KE = 66*9.8*5.0 = 32340 J
B
add them all by direction
13 East
10 West
subtract difference
3 E
. Methylated spirits have ethanol as a base but may include methyl alcohol (methanol) as part of the denaturing process.