Given:
Mass of the rail road car, m = 2 kg
velocity of the three cars coupled system, v' = 1.20 m/s
velocity of first car, 
= 3 m/s
Solution:
a) Momentum of a body of mass 'm' and velocity 'v' is given by:
p = mv
Now for the coupled system according to law of conservation of momentum, total momentum of a system before and after collision remain conserved:
(1)
where,
= velocity of the first car
= velocity of the 2 coupled cars after collision
Now, from eqn (1)
v' = 1.80 m/s
Therefore, the velocity of the combined car system after collision is 1.80 m/s
The answer is A because it was 2 minutes and she weighs 100 lbs.... so 2(100)=200.... 200 lbs of work
Answer:
Explanation:
In first case we are interested in one time 6 in six rolls
Thus probability = number of chances required/Total chances
= 1/6
Similarly in the second case probability = 2/12 = 1/6
In the same way in last case probability = 100/600 = 1/6
The probability is the same . Thus all the cases has equal chances
Answer:
Water gains energy during evaporation and releases it during condensation in the atmosphere
Explanation:
In the water cycle, heat energy is gained or lost by water as it undergoes various processes in the cycle.
In evaporation, water molecules gains energy because the molecules of water vibrate faster and become more energetic. Hence they are able to escape into the atmosphere from the surface of the liquid.
In condensation, the molecules of gaseous water looses energy and becomes liquid.
Hence, water gains energy during evaporation and releases it during condensation in the atmosphere.
