Given :
The ball of a ballpoint pen is 0.5 mm in diameter and has an ASTM grain size of 12.
To Find :
How many grains are there in the ball?
Solution :
Volume of ball of the ballpoint is :
Now, grain size of 12 has about 520000 grains/mm³.
Therefore, number of grains are :
Because the waves in the water with the fan like system.
The best transition between the four options presented to represent a time when water molecules are moving closer together would be A. Frost forms on a window pane.
The closest distance that the water molecules can do is when the water is in the state of being solid. It is known that the solid state of matter has the closest distance from molecule to molecule that when a molecule tries to move, the others move as well creating a vibration and thus producing heat in the process. When they are in a liquid state, they are quite far from each other. In a gas state, they really are far from each. This explains the difference in their characteristics.
Answer:
A.) 1430 metres
B.) 80 seconds
Explanation:
Given that the train accelerates from rest at 1.1m/s^2 for 20s. The initial velocity U will be:
U = acceleration × time
U = 1.1 × 20 = 22 m/s
It then proceeds at constant speed for 1100 m
Then, time t will be
Time = distance/ velocity
Time = 1100/22
Time = 50 s
before slowing down at 2.2m/s^2 until it stops at the station.
Deceleration = velocity/time
2.2 = 22/t
t = 22/2.2
t = 10s
Using area under the graph, the distance between the two stations will be :
(1/2 × 22 × 20) + 1100 + (1/2 × 22 × 10)
220 + 1100 + 110
1430 m
The time taken between the two stations will be
20 + 50 + 10 = 80 seconds
