Answer:
The principle of momentum conservation states that if there no external force the total momentum of the system before and after the collision is conserved.
Since momentum is a vector, we should investigate the directions and magnitudes of initial and final momentum.
If the first ball hits the second ball with an angle, we should separate the x- and y-components of the momentum (or velocity), and apply conservation of momentum separately on x- and y-directions.
Answer:
C) steel turning to rust in salt air
Explanation:
The missing options are:
A) ice melting to form liquid water
B) water boiling to form steam
C) steel turning to rust in salt air
D) sugar dissolving into hot coffee
In a chemical change the atoms of the reacting compounds are reordered forming new compounds. In a chemical change, new compounds appear, but in a physical change not.
Then, change of states like ice melting and water boiling are not chemical changes.
During steel rust, components of steel, like iron, are oxidized, that is, reacts with oxygen forming oxides.
The dissolution of sugar into hot coffee is a physical change in which sugar molecules get further apart in the coffee, but they don't change.
"(1) a satellite moving around Earth in a circular <span>orbit" is the only option from the list that describes an object in equilibrium, since velocity and gravity are working together to keep the orbit constant. </span>
The temperature of the lithosphere is around 300<span>°C</span> - 500<span>°<span>C</span></span>
Answer:
Explanation:
Given that,
Frequency of radio signal is
f = 800kHz = 800,000 Hz.
Distance from transmitter
d = 8.5km = 8500m
Electric field amplitude
E = 0.9 V/m
The average energy density can be calculated using
U_E = ½•ϵo•E²
Where ϵo = 8.85 × 10^-12 F/m
Then,
U_E = ½ × 8.85 × 10^-12 × 0.9²
U_E = 3.58 × 10^-12 J/m²
The average electromagnetic energy density is 3.58 × 10^-12 J/m²
