Let car A's starting position be the origin, so that its position at time <em>t</em> is
A: <em>x</em> = (40 m/s) <em>t</em>
and car B has position at time <em>t</em> of
B: <em>x</em> = 100 m - (60 m/s) <em>t</em>
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They meet when their positions are equal:
(40 m/s) <em>t</em> = 100 m - (60 m/s) <em>t</em>
(100 m/s) <em>t</em> = 100 m
<em>t</em> = (100 m) / (100 m/s) = 1 s
so the cars meet 1 second after they start moving.
They are 100 m apart when the difference in their positions is equal to 100 m:
(40 m/s) <em>t</em> - (100 m - (60 m/s) <em>t</em>) = 100 m
(subtract car B's position from car A's position because we take car A's direction to be positive)
(100 m/s) <em>t</em> = 200 m
<em>t</em> = (200 m) / (100 m/s) = 2 s
so the cars are 100 m apart after 2 seconds.
centrifugal force is a fictitious force. What is happening is that since the earth itself is not a rigid body it will deform when under motion. Although gravity attempts to make the earth spherical, as it is rotating the earth deforms, in such away that it flattens to become an oblique spheroid. This happens as the material at the equator must have a net resultant centripetal force (not centrifugal) which causes its position of equilibrium from the center of the earth to be further away than at the poles as they do not have this force as they are not rotating around the center of mass.
30 minutes I am not sure about that
Answer:
the final energy of the system is 35.5 kJ.
Explanation:
Given;
initial energy of the system, E₁ = 10 kJ
heat transferred to the system, q₁ 30 kJ
Heat lost to the surrounding, q₂ = 5kJ
heat gained by the system, Q = q₁ - q₂ = 30 kJ - 5kJ = 25 kJ
work done on the system, W = 500 J = 0.5 kJ
Apply first law of thermodynamic,
ΔU = Q + W
where;
ΔU is change in internal energy
Q is the heat gained by the system
W is work done on the system
ΔU = 25kJ + 0.5 kJ
ΔU = 25.5 kJ
The final energy of the system is calculated as;
E₂ = E₁ + ΔU
E₂ = 10 kJ + 25.5 kJ
E₂ = 35.5 kJ.
Therefore, the final energy of the system is 35.5 kJ.
