Answer:
Your answer should be Cooled Air
Explanation:
Answer:
<em>The average speed of the train is 45 km/h</em>
Explanation:
<u>Speed</u>
It's defined as the distance (d) per unit of time (t) traveled by an object. The formula is:
Let's call x the total distance covered by the train. It covered d1=1/3x with a speed of v1=25 km/h. The time taken is calculated solving for t:
Now the rest of the distance:
d2 = x - 1/3x = 2/3x
Was covered at v2=75 km/h. Thus the time taken is:
The total time is:
Simplifying:
The average speed is the total distance divided by the total time:
Simplifying:
The average speed of the train is 45 km/h
Answer:
Explanation:
= Activation energy = 160 kJ
T = Temperature = 510 K
R = Universal gas constant = 8.314 J/mol K
The fraction of energy is given by
The fraction of energy is
Answer:
There is an arrow up for air resistance and an arrow down for gravity. The arrow up is longer than the arrow down.
Explanation:
The text of the problem says that the skydiver is slowing down: this means that he has an acceleration, which is directed opposite to the motion of the skydiver. Since the motion is downward, the acceleration must be upward.
There are two forces acting on the skydiver: the gravity (downward) and the air resistance (upward). According to Newton's second law:
F=ma
the acceleration has the same direction of the net force, so the net force must also be upward: therefore, the air resistance must be greater than the gravity, so the arrow up for air resistance is longer than the arrow down for gravity.