If he feels like, is interested in it, and is able to grasp it, then why not ? Why not indeed ?
Answer:
1. 37.8J
2. 18 Billion Joules, 18 Gigajoules
3. 9.81 Billion Joules, 9.81 Gigajoules
Explanation:
Use the formulas provided,
KE=(1/2)mv^2 and PE=mgh, noting that g=9.81
ANSWER
C. 
. newtons
EXPLANATION
According to Newton's second law,
, where
is the mass measured in kilograms.
and
is the acceleration in metres per second square.
We substitute these values to obtain,
.
We rearrange to get,
.
We multiply out the first two numbers and leave our answer in standard form to get,
.
The correct answer is C
"1 Ampere" (A) means "1 coulomb of charge per second"
140 A means 140 coulombs per second
(140 coulomb/sec) x (0.9 sec) = 126 coulombs of charge.
Go a little farther:
Electrons are the things that move through wire carrying charge.
6.25 x 10¹⁸ electrons carry 1 coulomb of charge.
126 coulombs = 787,500,000,000,000,000,000 electrons (rounded)
