Answer: i think thats the answer
≈
40.8
kg
Explanation:
Well, assuming the boy is on Earth, then the gravitational acceleration is approximately
9.8
m/s
2
.
So, we get:
m
=
W
g
=
400
N
9.8
m/s
2
≈
40.8
kgExplanation:
Oxygen has Atomic number 8 so all isotopes have 8 protons and 8 electrons.
So the number of neutrons in Oxygen-18 = 18 - 8 = 10.
Option B is the correct one.
....................................
Hubble noticed that the galaxies were moving away from us, which meant the universe was expanding.
This is why constellations change over time. In some years, the Big Dipper won't actually look like a dipper anymore.
A) Agreed.
<span>b) Value agreed but units should be W (watts). </span>
<span>c) Here's one method... </span>
<span>15 miles = 24140 m </span>
<span>1 gallon of gasoline contains 1.4×10⁸ J. </span>
<span>So moving a distance of 24140m requires gasoline containing 1.4×10⁸ J </span>
<span>Therefore moving a distance of 1m requires gasoline containing 1.4×10⁸/24140 = 5800 J </span>
<span>Overcoming rolling resitance for 1m requires (useful) work = force x distance = 1000x1 = 1000J </span>
<span>So 5800J (in the gasoline) provides 1000J (overcoming rolling resistance) of useful work for each metre moved. </span>
<span>Efficiency = useful work/total energy supplied </span>
<span>= 1000/5800 </span>
<span>= 0.17 (=17%) </span>
