Answer:
The average velocity is 50 km/h south
Explanation:
The average velocity of an object is its total displacement divided by
the total time taken.
That means it is the rate at which an object changes its position from
one place to another.
Average velocity is a vector quantity.
The SI unit is meters per second.
A bicycle that starts 100 km south and is 120 km south of town after
0.4 hour.
The displacement = 120 - 100 = 20 km south
The time = 0.4 hour
The average velocity = 
, where D is the displacement
and t is the time
The average velocity of the bicycle = 
km/h
<em>The average velocity is 50 km/h south</em>
If you want it in meter per second, change the kilometer to meter
and change the hour to seconds
1 km = 1000 m
1 hour = 60 × 60 = 3600 seconds
The average velocity of the bicycle = 
m/s south
Answer:
It may not be at the sea level
Explanation:
The reason here is water only boils at sea level. This means that if you move water to a different height, say top of a mountain, the boiling temperature of water would change. This is due to the pressure drop at high place. The drop of pressure would make it harder to transform water liquid to gas, thus requiring more temperature.
Explanation:
The temperature must be hot enough to allow the ions of deuterium and tritium to have enough kinetic energy to overcome the Coulomb barrier and fuse together. The ions must be confined with a high ion density to achieve a suitable fusion reaction rate.
Yes that answer is correct because sometimes tides cause waves to happen
Answer:
Since strong nuclear forces involve only nuclear particles (not electrons, bonds, etc) items 3 and 4 are eliminated.
Again item 2 refers to bonds between atoms and is eliminated.
This leaves only item 1.
Nuclear forces are very short range forces between components of the nucleus.
Weak nuclear forces are trillions of times smaller than strong forces.
Gravitational forces are much much smaller than the weak nuclear force.
